Docker: Difference between revisions

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* https://docs.docker.com/desktop/linux/install/
* https://docs.docker.com/desktop/linux/install/
* [https://www.docker.com/blog/the-magic-of-docker-desktop-is-now-available-on-linux/ The Magic of Docker Desktop is Now Available on Linux]
* [https://www.docker.com/blog/the-magic-of-docker-desktop-is-now-available-on-linux/ The Magic of Docker Desktop is Now Available on Linux]
* [https://ostechnix.com/docker-desktop-for-linux/ A Beginners Manual To Docker Desktop For Linux]


== Without sudo, Post-installation ==
== Without sudo, Post-installation ==
Line 131: Line 132:


== Windows ==
== Windows ==
Note many of the information here have not been updated.
Docker can be run on Windows 10 Pro as a native application; see  
Docker can be run on Windows 10 Pro as a native application; see  
* https://docs.docker.com/engine/installation/windows/.
* https://docs.docker.com/engine/installation/windows/.
Line 367: Line 370:


=== WSL2 ===
=== WSL2 ===
[https://poweruser.blog/docker-on-windows-10-without-hyper-v-a529897ed1cc Docker on Windows without Hyper-V]
* [https://poweruser.blog/docker-on-windows-10-without-hyper-v-a529897ed1cc Docker on Windows without Hyper-V]
* [https://docs.microsoft.com/en-us/windows/wsl/install-manual Manual installation steps for older versions of WSL]. I got this page when I installed Docker Desktop v4.9.0 (2022/6/14) on Windows 10.


== Mac ==
== Mac ==
https://docs.docker.com/desktop/mac/
* https://docs.docker.com/desktop/mac/
 
* Alternatives to Docker Desktop for Mac? Rancher is recommended. 2022-06-08
If you have Mac, you don't have to use boot2docker (iso & its management tool). You can use other Linux which comes with docker pre-installed. See [https://serversforhackers.com/getting-started-with-docker/ this post].
* Vagrant method. If you have Mac, you don't have to use boot2docker (iso & its management tool). You can use other Linux which comes with docker pre-installed. See [https://serversforhackers.com/getting-started-with-docker/ this post].


== ARM architeture from hub.docker.com ==
== ARM architeture from hub.docker.com ==
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</pre>
</pre>


== GUI/TUI interface manager ==
== How and Why to Use A Remote Docker Host ==
=== [https://github.com/moncho/dry Dry] ===
* [https://www.cloudsavvyit.com/11185/how-and-why-to-use-a-remote-docker-host/ How and Why to Use A Remote Docker Host]
[https://www.2daygeek.com/dry-an-interactive-cli-manager-for-docker-containers/ Dry – An Interactive CLI Manager For Docker Containers]. The TUI is built on top of [https://github.com/gizak/termui termui]; a cross-platform, easy-to-compile, and fully-customizable terminal dashboard. It is inspired by [https://github.com/yaronn/blessed-contrib blessed-contrib], but purely in Go.
* [https://www.cloudsavvyit.com/12514/how-docker-contexts-let-you-work-with-multiple-hosts/ How Docker Contexts Let You Work with Multiple Hosts]


=== LazyDocker (TUI) ===
== Backup ==
[https://www.linuxuprising.com/2019/07/lazydocker-new-docker-and-docker.html?m=1 LazyDocker: New Docker And Docker Compose Terminal UI], [https://github.com/jesseduffield/lazydocker Github]
* [https://docs.docker.com/storage/volumes/#backup-restore-or-migrate-data-volumes Backup, restore, or migrate data volumes]
* [https://stackoverflow.com/a/28145912 Backup a running Docker container?]
* [https://www.maketecheasier.com/copy-move-docker-container-to-another-host/ How to Copy/Move a Docker Container to Another Host]
* [https://www.reddit.com/r/docker/comments/vi0o4k/comment/idbndut/?utm_source=share&utm_medium=web2x&context=3 Is backing up `/var/lib/docker/volumes` a good way to back up your Docker containers? If not, what is?]


It works on ARM devices too.
= Usage =
== Basics, docs, cheatsheet ==
* https://docs.docker.com/articles/basics/
* [https://www.fosstechnix.com/docker-command-cheat-sheet/ 81 Docker Command Cheat Sheet with Description]
* https://coderwall.com/p/2es5jw/docker-cheat-sheet-with-examples
* https://github.com/wsargent/docker-cheat-sheet
* [https://www.howtoforge.com/tutorial/how-to-use-docker-introduction/ How to use Docker in a practical way]
* https://hackernoon.com/introduction-to-docker-a7d9e1f6c0b3#.tezit0hkq
* [http://www.cnblogs.com/wanliwang01/p/docker01.html Docker快速入门]
* [http://blog.myplanet.com/docker-the-fun-and-easy-way Docker: The Fun and Easy Way]


=== Dockly (TUI) ===
Note that we need '''sudo''' is needed unless it is on a Mac OS.
[https://www.ostechnix.com/dockly-manage-docker-containers-from-terminal/ Dockly – Manage Docker Containers From Terminal]


=== DockStation ===
If docker cannot find an image, it will try to pull it from its repository.
It is not open source. It works with remote Docker containers.
<pre>
$ sudo docker run -it ubuntu /bin/bash
Unable to find image 'ubuntu' locally
Pulling repository ubuntu
04c5d3b7b065: Download complete
511136ea3c5a: Download complete
c7b7c6419568: Download complete
70c8faa62a44: Download complete
d735006ad9c1: Download complete
root@ec83b3ac878d:/#
</pre>


* [https://github.com/DockStation/dockstation DockStation]
{| class="wikitable"
* [https://www.upnxtblog.com/index.php/2018/01/17/top-6-gui-tools-for-managing-docker-environments/ TOP 6 GUI tools for managing Docker environments] 2018
! purpose
* [https://www.how2shout.com/tools/4-best-docker-gui-tools-to-manage-containers-graphically.html 4 Best Docker GUI tools to manage containers graphically] 2019
! command
 
|-
=== DockSTARTer: get started with home server apps running in Docker ===
| run a container
* https://dockstarter.com/
| docker container run -d -p 80:80 httpd
* [https://www.makeuseof.com/tag/setup-linux-media-server/ How to Set Up a Linux Media Server in Under One Hour]
|-
 
| list running cotainer
=== [https://portainer.io/ Portainer]* (nice) ===
| docker container ls
<ul>
|-
<li>[https://github.com/portainer/portainer/issues/5406 Hardware minimum requirements] 100MB RAM. That's why 1GB ram of Raspberry Pi works fine.
| view logs of Docker container
<li>[https://docs.portainer.io/start/install/server/docker/linux Install], [https://docs.portainer.io/ Documentation]
| docker container logs cranky_cori
<pre>
|-
docker volume create portainer_data
| identify Docker container process?
docker run -d -p 8000:8000 -p 9443:9443 \
| docker container top  cranky_cori
  --name portainer \
|-
  --restart=always \
| stop Docker container?
  -v /var/run/docker.sock:/var/run/docker.sock \
| docker container stop cranky_cori
  -v portainer_data:/data portainer/portainer-ce:latest
|-
| list stopped or not running Docker containers
| docker container ls -a
|-
| start Docker container
| docker container start c46f2e9e4690
|-
| remove Docker container
| docker container rm cranky_cori
|-
| list Docker images
| docker images
|-
| remove Docker image
| docker rmi iman/touch
|}
 
=== Restart docker daemon ===
When I try the Chap5 > Continuous integration (Jenkins) of the Docker Book, I found I cannot stop/kill the container. See others' report [https://github.com/docker/docker/issues/1906 here]. The solution is to restart the docker daemon.
<pre>
sudo service docker start
</pre>
</pre>
By default, Portainer Server will expose the UI over port 9443 and expose a TCP tunnel server over port 8000. The latter is optional and is only required if you plan to use the Edge compute features with Edge agents.
After that, I can stop and rm the container.
</li>
<pre>
<li>Access https://localhost:9443 </li>
sudo docker stop jenkins
<li>Portainer itself is a docker application. </li>
sudo docker rm jenkins
<li>[https://docs.portainer.io/advanced/reset-admin Reset the admin user's password].</li>
sudo docker ps -a
<li>[https://youtu.be/M365jgJ0O2E How to Update Portainer Fast, Simple, and Easy Guide]. docker stop + docker rm + docker rmi + docker run.
</pre>
</li>
 
<li>[https://dbtechreviews.com/2020/08/update-portainer-to-version-2-0-super-easy/ Update Portainer to Version 2.0 – Super Easy!]. When the first time accessing http://localhost:9000, you need to create a password (at least 8 characters long) for the default user "admin".
=== images vs containers ===
{{Pre}}
$ docker volume create portainer_data
$ docker run -d -p 9000:9000 -p 8000:8000 --name portainer --restart always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce
</pre>
* [https://dbtechreviews.com/2020/09/using-application-templates-in-portainer-2-0/ Using Application Templates in Portainer 2.0]
* [https://youtu.be/BwgKd6LohQo Install 80+ Docker Images In Seconds Using This Portainer App Template] (video)
* [https://youtu.be/2oi4IQF7VnE Raspberry Pi Home Server Episode 5: Remote Access with NGINX Proxy Manager]
* [https://youtu.be/ji0kgXhXR6g Raspberry Pi Home Server Episode 8: BitWardenRS - Password Manager with Remote Access] (video)
* [https://dbtechreviews.com/2020/07/install-nextcloud-on-a-raspberry-pi-4-with-openmediavault-and-docker/ Install NextCloud on a Raspberry Pi 4 with OpenMediaVault and Docker]
</li>
<li>Update from 2.11 to 2.13 (The password must be at least 12 characters long)
<ul>
<li>Step 1: [https://dbtechreviews.com/2021/08/how-to-update-portainer-to-the-newest-version/ How to Update Portainer to the Newest Version]
<pre>
<pre>
sudo docker stop portainer && sudo docker rm portainer
$ sudo docker images
docker pull portainer/portainer-ce:latest
REPOSITORY                    TAG                IMAGE ID            CREATED              VIRTUAL SIZE
</pre>
iman                          latest             6e0f5644b2fd        About a minute ago  460.4 MB
</li>
iman/touch                    latest              77b9ac5951c2        4 minutes ago        460.4 MB
<li>Step 2: [https://docs.portainer.io/start/upgrade/docker Upgrading on Docker Standalone]
<none>                         <none>             aaa75e64ddf0        5 weeks ago          188.3 MB
{{Pre}}
ouruser/sinatra                v2                  ea8c9f407a8d        5 weeks ago          447 MB
docker run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce:latest
ubuntu                         14.04               ed5a78b7b42b        5 weeks ago          188.3 MB
</pre>
ubuntu                        latest              ed5a78b7b42b        5 weeks ago          188.3 MB
</li>
eddelbuettel/docker-ubuntu-r  add-r-devel-san    3c19d078c5d9        3 months ago        460.4 MB
</ul>
hello-world                    latest              ef872312fe1b        4 months ago        910 B
</ul>
training/sinatra              latest              f0f4ab557f95        8 months ago        447 MB
* [https://github.com/portainer/portainer-docs/issues/91 Why port 8000 is needed to be published?], [https://forums.portainer.io/t/what-port-8000-used-for-do-i-need-to-expose-it/210 What port 8000 used for? Do I need to expose it?]
* [https://dzone.com/articles/a-comparison-of-docker-guis A Comparison of Docker GUIs]. A username/password is required to access the page unless we use the '''--no-auth''' option; see [https://portainer.readthedocs.io/en/stable/configuration.html Configuration].
* [https://www.howtoforge.com/tutorial/ubuntu-docker-portainer/ How to Manage Docker Containers using Portainer on Ubuntu 16.04]. Go to Local. It will show the status of all local stacks, containers, volumes and images. Very Cool!
* [https://www.linuxtechi.com/monitor-manage-docker-containers-portainer-part1/ Monitor and Manage Docker Containers with Portainer.io (GUI tool) – Part-1] 2019
* [https://www.reddit.com/r/portainer/comments/v3uyo3/best_and_most_uptodate_portainer_app_template_for/?utm_source=share&utm_medium=web2x&context=3 Best and most up-to-date Portainer app template for selfhosting?] 2022-06-03
* [https://youtu.be/BwgKd6LohQo Install 80+ Docker Images In Seconds Using This Portainer App Template] (video, 2020)
** Default on my Portainer 2.0.1 (see logs for version number) https://raw.githubusercontent.com/portainer/templates/master/templates-2.0.json
** https://raw.githubusercontent.com/SelfhostedPro/selfhosted_templates/portainer-2.0/Template/template.json (working), [https://github.com/SelfhostedPro/selfhosted_templates Github]
** https://raw.githubusercontent.com/nashosted/self-hosted-template/master/template.json (working)
** Alternative: [https://github.com/Taisun-Docker/taisun taisun]
* [https://www.cloudsavvyit.com/8911/how-to-get-started-with-portainer-a-web-ui-for-docker/ How to Get Started With Portainer, a Web UI for Docker]
* [https://www.linuxtechi.com/monitor-manage-docker-containers-portainer-io-part-2/ Monitor and Manage Docker Containers with Portainer.io (GUI tool) – Part-2]
* [https://collabnix.com/portainer-vs-rancher/ Portainer Vs Rancher]
* [https://youtu.be/XYcKmPi4McA How-to: Deploy Portainer on MicroK8s] (video)
* [https://www.portainer.io/blog/from-zero-to-production-with-fedora-coreos-portainer-and-wordpress-in-7-easy-steps From Zero to Production with Fedora CoreOS, Portainer, and WordPress in 7 Easy Steps]. Virtualbox was used


=== Yacht ===
$ sudo docker ps -a
* https://yacht.sh/Installation/yacht/
CONTAINER ID IMAGE                                          COMMAND              CREATED        STATUS                  PORTS NAMES
* [https://youtu.be/KstIS5DstTE Yacht Installed on Docker - Portainer Alternative] (video)
8fbdbcdb5126 iman/touch:latest                              "/bin/bash"          2 minutes ago  Exited (0) 2 minutes ago      thirsty_engelbart 
 
dc9e82f2c00a eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          9 minutes ago  Exited (0) 3 minutes ago      kickass_bardeen   
=== cockpit-docker ===
532a90f36aa8 eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          18 hours ago  Exited (0) 18 hours ago        happy_lalande     
* [https://www.hostwinds.com/guide/installing-and-using-cockpit-docker-linux-vps/ Installing And Using Cockpit-Docker]
7634024ee0bf eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          18 hours ago  Exited (0) 18 hours ago        insane_mclean     
* The default port is 9090.
14034a9720cb eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          18 hours ago  Exited (0) 18 hours ago        naughty_lumiere   
* Not useful for manager docker containers.
ca90954628db eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          19 hours ago  Exited (130) 18 hours ago      sick_hawking       
<pre>
8bbdcb7c339f eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          19 hours ago  Exited (0) 19 hours ago        modest_davinci     
sudo apt-get -y install cockpit-docker
e8e24f80f0dd aaa75e64ddf0                                  "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago      berserk_hodgkin   
d41959e0eb55 aaa75e64ddf0                                  "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago      jovial_curie       
b408c0e2805b aaa75e64ddf0                                  "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago      lonely_tesla       
72a551e4b492 ouruser/sinatra:v2                            "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago        jolly_meitner     
75fd6cc4658b training/sinatra:latest                        "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago        evil_yalow         
cc8886f5a02e training/sinatra:latest                        "/bin/bash"          5 weeks ago    Exited (130) 5 weeks ago      elegant_curie     
0585e4f5fecd eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago        elated_euclid     
brb@brbweb4:~/Downloads$
</pre>
 
When we want to delete a container, we use the container's '''CONTAINER ID''' or '''NAME''' (last column output from docker ps -a). But when we want to delete an image, we use the image's '''REPOSITORY''' or '''IMAGE ID''' (2nd column output from docker images)
<pre>
$ sudo docker rm thirsty_engelbart  # iman/touch
$ sudo docker rm dc9e82f2c00a      # eddelbuettel/docker-ubuntu-r:add-r-devel-san
$ sudo docker ps -a  # check to see the container is gone now


sudo systemctl restart cockpit
$ sudo docker rmi 6e0f5644b2fd
$ sudo docker rmi iman/touch
$ sudo docker images  # check to see the images are gone now
</pre>
</pre>


=== [https://github.com/crosbymichael/dockerui DockerUI] (Deprecated, Development continues at Portainer)===
=== Command line interface, CLI ===
https://github.com/kevana/ui-for-docker. A quick start:
https://docs.docker.com/engine/reference/commandline/cli/ Docker command line
# Run:  <syntaxhighlight lang='bash'>
<pre>
docker run -d -p 9000:9000 --privileged \
$ docker
    -v /var/run/docker.sock:/var/run/docker.sock uifd/ui-for-docker
</syntaxhighlight> where '''-v''' means to bind mount a volume.
# Open your browser to http://<dockerd host ip>:9000


Note: Anyone in the local network can access the website without any authentication.
Usage: docker COMMAND


=== Rancher ===
A self-sufficient runtime for containers
* https://rancher.com/quick-start/. The doc above is not good enough to follow. Search Google for tutorial or get started guide including screenshots.
* [https://www.howtoforge.com/tutorial/ubuntu-rancher-docker-container-manager/ How to Manage Docker Containers with Rancher on Ubuntu 16.04]
* [https://hackernoon.com/creating-a-scalable-application-using-docker-rancher-rancheros-cattle-5feb83a3e743 Creating A Scalable Application Using Docker + Rancher + RancherOs + Cattle]
* Initial setup video https://youtu.be/1EMW1y7529Y
* Training from Rancher Labs https://youtu.be/8K14A_CZFdI. It seems Rancher is complicated but powerful. The whole operation is like Amazon Cloud.
* [https://gist.github.com/lmmendes/fbed32a452cf02d2a1095658795cb3d2 Running Rancher locally (with two hosts) using MacOS Docker and VirtualBox]
* To allow UDP port
<syntaxhighlight lang='bash'>
$ sudo apt-get install ufw
$ sudo ufw allow 4500/udp
$ sudo ufw allow 500/udp
</syntaxhighlight>
* discoposse.com
** [http://discoposse.com/2015/11/08/rancher-part-1-installing-rancher-and-setting-access-control/ Part 1] Installing Rancher and Setting Access Control
** [http://discoposse.com/2015/11/09/rancher-part-2-adding-a-docker-host-to-rancher/ Part 2] Adding a Docker Host to Rancher
** [http://discoposse.com/2015/11/12/rancher-part-3-adding-the-dockerhub-to-our-rancher-registry/ Part 3] Adding the DockerHub to our Rancher Registry
** [http://discoposse.com/2015/11/13/rancher-part-4-using-the-catalog-example-with-glusterfs/ Part 4] Using the Catalog Example with GlusterFS


=== [https://github.com/tobegit3hub/seagull Seagull] ===
Options:
https://youtu.be/TuT5gb8oRw8
      --config string      Location of client config files (default "/home/brb/.docker")
  -D, --debug              Enable debug mode
  -H, --host list          Daemon socket(s) to connect to
  -l, --log-level string  Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
      --tls                Use TLS; implied by --tlsverify
      --tlscacert string  Trust certs signed only by this CA (default "/home/brb/.docker/ca.pem")
      --tlscert string    Path to TLS certificate file (default "/home/brb/.docker/cert.pem")
      --tlskey string      Path to TLS key file (default "/home/brb/.docker/key.pem")
      --tlsverify          Use TLS and verify the remote
  -v, --version            Print version information and quit


<pre>
Management Commands:
docker run -d -p 127.0.0.1:10086:10086 -v /var/run/docker.sock:/var/run/docker.sock tobegit3hub/seagull
  config      Manage Docker configs
</pre>
  container  Manage containers
  image      Manage images
  network    Manage networks
  node        Manage Swarm nodes
  plugin      Manage plugins
  secret      Manage Docker secrets
  service    Manage services
  swarm      Manage Swarm
  system      Manage Docker
  trust      Manage trust on Docker images
  volume      Manage volumes


The only issue is there is no username/password to protect other people to access the web GUI. The solution of binding to localhost to restrict the access does not work for remote administration.
Commands:
 
  attach      Attach local standard input, output, and error streams to a running container
That is, the tool is suitable for home use.
  build      Build an image from a Dockerfile
 
  commit      Create a new image from a container's changes
=== [https://kitematic.com/ Kitematic] (Mac, Windows and Ubuntu) ===
  cp          Copy files/folders between a container and the local filesystem
Owned by Docker. Available for Mac OS X 10.8+ and Windows 7+ (64-bit) and Ubuntu. https://github.com/docker/kitematic/releases/
  create      Create a new container
 
  diff        Inspect changes to files or directories on a container's filesystem
Run containers through a simple, yet powerful graphical user interface.
  events      Get real time events from the server
 
  exec        Run a command in a running container
It can not connect to remote docker machines.
  export      Export a container's filesystem as a tar archive
 
  history    Show the history of an image
A [https://www.r-bloggers.com/share-your-shiny-apps-with-docker-and-kitematic/ Share your Shiny Apps with Docker and Kitematic!]
  images      List images
  import      Import the contents from a tarball to create a filesystem image
  info        Display system-wide information
  inspect    Return low-level information on Docker objects
  kill        Kill one or more running containers
  load        Load an image from a tar archive or STDIN
  login      Log in to a Docker registry
  logout      Log out from a Docker registry
  logs        Fetch the logs of a container
  pause      Pause all processes within one or more containers
  port        List port mappings or a specific mapping for the container
  ps          List containers
  pull        Pull an image or a repository from a registry
  push        Push an image or a repository to a registry
  rename      Rename a container
  restart    Restart one or more containers
  rm          Remove one or more containers
  rmi        Remove one or more images
  run        Run a command in a new container
  save        Save one or more images to a tar archive (streamed to STDOUT by default)
  search      Search the Docker Hub for images
  start      Start one or more stopped containers
  stats      Display a live stream of container(s) resource usage statistics
  stop        Stop one or more running containers
  tag        Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
  top        Display the running processes of a container
  unpause    Unpause all processes within one or more containers
  update      Update configuration of one or more containers
  version    Show the Docker version information
  wait        Block until one or more containers stop, then print their exit codes


=== [https://github.com/shipyard/shipyard Shipyard] (retired) ===
Run 'docker COMMAND --help' for more information on a command.
* [https://www.sumologic.com/blog/code/managing-containers-docker-shipyard/ Managing Containers with Docker Shipyard]
</pre>
* Three alternatives:
** [http://rancher.com/ Rancher]
** [https://github.com/kevana/ui-for-docker Docker UI]
** [https://portainer.io/ Portainer]


=== VS Code ===
=== Version, system information ===
* [https://youtu.be/i7ABlHngi1Q Docker For Beginners: From Docker Desktop to Deployment]
Docker version
* [https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers Visual Studio Code Remote - Containers]
<syntaxhighlight lang='bash'>
* [https://www.docker.com/blog/how-to-develop-inside-a-container-using-visual-studio-code-remote-containers/ How to Develop Inside a Container Using Visual Studio Code Remote Containers]
$ docker version
* [https://www.cloudsavvyit.com/12837/how-to-edit-code-in-docker-containers-with-visual-studio-code/ How to Edit Code in Docker Containers With Visual Studio Code]
Client:
Version:           18.06.1-ce
API version:      1.38
Go version:       go1.10.3
Git commit:        e68fc7a
Built:            Tue Aug 21 17:24:51 2018
OS/Arch:          linux/amd64
Experimental:     false


== How and Why to Use A Remote Docker Host ==
Server:
* [https://www.cloudsavvyit.com/11185/how-and-why-to-use-a-remote-docker-host/ How and Why to Use A Remote Docker Host]
Engine:
* [https://www.cloudsavvyit.com/12514/how-docker-contexts-let-you-work-with-multiple-hosts/ How Docker Contexts Let You Work with Multiple Hosts]
  Version:          18.06.1-ce
  API version:      1.38 (minimum version 1.12)
  Go version:       go1.10.3
  Git commit:      e68fc7a
  Built:            Tue Aug 21 17:23:15 2018
  OS/Arch:          linux/amd64
  Experimental:    false
</syntaxhighlight>


= Usage =
System information.
== Basics, docs, cheatsheet ==
* what mode the Docker engine is operating in (swarm mode or not)
* https://docs.docker.com/articles/basics/
* what storage drive is used for the union filesystem
* https://www.docker.com/sites/default/files/d8/2019-09/docker-cheat-sheet.pdf
* what version of the Linux kernel we have on our host
* https://coderwall.com/p/2es5jw/docker-cheat-sheet-with-examples
* et al
* https://github.com/wsargent/docker-cheat-sheet
<syntaxhighlight lang='bash'>
* [https://www.howtoforge.com/tutorial/how-to-use-docker-introduction/ How to use Docker in a practical way]
$ docker system info
* https://hackernoon.com/introduction-to-docker-a7d9e1f6c0b3#.tezit0hkq
Containers: 2
* [http://www.cnblogs.com/wanliwang01/p/docker01.html Docker快速入门]
Running: 0
* [http://blog.myplanet.com/docker-the-fun-and-easy-way Docker: The Fun and Easy Way]
Paused: 0
 
Stopped: 2
Note that we need '''sudo''' is needed unless it is on a Mac OS.
Images: 10
 
Server Version: 18.06.1-ce
If docker cannot find an image, it will try to pull it from its repository.
Storage Driver: overlay2
<pre>
Backing Filesystem: extfs
$ sudo docker run -it ubuntu /bin/bash
Supports d_type: true
Unable to find image 'ubuntu' locally
Native Overlay Diff: true
Pulling repository ubuntu
Logging Driver: json-file
04c5d3b7b065: Download complete
Cgroup Driver: cgroupfs
511136ea3c5a: Download complete
Plugins:
c7b7c6419568: Download complete
Volume: local
70c8faa62a44: Download complete
Network: bridge host macvlan null overlay
d735006ad9c1: Download complete
Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
root@ec83b3ac878d:/#
Swarm: inactive
</pre>
Runtimes: runc
 
Default Runtime: runc
{| class="wikitable"
Init Binary: docker-init
! purpose
containerd version: 468a545b9edcd5932818eb9de8e72413e616e86e
! command
runc version: 69663f0bd4b60df09991c08812a60108003fa340
|-
init version: fec3683
| run a container
Security Options:
| docker container run -d -p 80:80 httpd
apparmor
|-
seccomp
| list running cotainer
  Profile: default
| docker container ls
Kernel Version: 4.15.0-33-generic
|-
Operating System: Ubuntu 18.04.1 LTS
| view logs of Docker container
OSType: linux
| docker container logs cranky_cori
Architecture: x86_64
|-
CPUs: 4
| identify Docker container process?
Total Memory: 7.674GiB
| docker container top  cranky_cori
Name: t420s
|-
ID: VLWB:6BN3:U7KB:L4T4:GQIB:54F3:YZKJ:PAIR:HEUM:UQIC:XLZU:3IFJ
| stop Docker container?
Docker Root Dir: /var/lib/docker
| docker container stop cranky_cori
Debug Mode (client): false
|-
Debug Mode (server): false
| list stopped or not running Docker containers
Registry: https://index.docker.io/v1/
| docker container ls -a
Labels:
|-
Experimental: false
| start Docker container
Insecure Registries:
| docker container start c46f2e9e4690
127.0.0.0/8
|-
Live Restore Enabled: false
| remove Docker container
 
| docker container rm cranky_cori
WARNING: No swap limit support
|-
</syntaxhighlight>
| list Docker images
 
| docker images
=== List resource consumption ===
|-
<syntaxhighlight lang='bash'>
| remove Docker image
$ docker system df
| docker rmi iman/touch
TYPE                TOTAL              ACTIVE              SIZE                RECLAIMABLE
|}
Images              10                  2                  2.58GB              1.519GB (58%)
Containers          2                  0                  304B                304B (100%)
Local Volumes      2                  0                  314.7MB            314.7MB (100%)
Build Cache        0                  0                  0B                  0B


=== Restart docker daemon ===
$ docker system df -v  # more detailed information
When I try the Chap5 > Continuous integration (Jenkins) of the Docker Book, I found I cannot stop/kill the container. See others' report [https://github.com/docker/docker/issues/1906 here]. The solution is to restart the docker daemon.
# We can use the information to clean up our system
<pre>
</syntaxhighlight>
sudo service docker start
</pre>
After that, I can stop and rm the container.
<pre>
sudo docker stop jenkins
sudo docker rm jenkins
sudo docker ps -a
</pre>


=== images vs containers ===
== [https://www.youtube.com/watch?v=umJYDAYxZys A brief intro to docker virtualization] ==
<pre>
<pre>
$ sudo docker images
docker search --help
REPOSITORY                    TAG                IMAGE ID            CREATED              VIRTUAL SIZE
docker search redis
iman                          latest              6e0f5644b2fd        About a minute ago  460.4 MB
docker search -s 100 redis
iman/touch                    latest              77b9ac5951c2        4 minutes ago        460.4 MB
docker pull --help
<none>                        <none>              aaa75e64ddf0        5 weeks ago          188.3 MB
docker pull ubuntu # download all versions of ubuntu
ouruser/sinatra                v2                  ea8c9f407a8d        5 weeks ago          447 MB
docker images    # available local container images
ubuntu                        14.04              ed5a78b7b42b        5 weeks ago          188.3 MB
docker pull centos:latest
ubuntu                        latest             ed5a78b7b42b        5 weeks ago          188.3 MB
docker run --help
eddelbuettel/docker-ubuntu-r   add-r-devel-san    3c19d078c5d9        3 months ago        460.4 MB
cat /etc/issue   # look at the current distr name before running docker
hello-world                    latest             ef872312fe1b        4 months ago        910 B
docker run -it centos:latest /bin/bash
training/sinatra              latest              f0f4ab557f95        8 months ago        447 MB
                # create a container & execute as a sudo


$ sudo docker ps -a
cat /etc/redhat-release
CONTAINER ID IMAGE                                          COMMAND              CREATED        STATUS                  PORTS NAMES
yum
8fbdbcdb5126 iman/touch:latest                              "/bin/bash"          2 minutes ago  Exited (0) 2 minutes ago      thirsty_engelbart 
cd /home
dc9e82f2c00a eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          9 minutes ago  Exited (0) 3 minutes ago      kickass_bardeen   
touch temp.txt
532a90f36aa8 eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          18 hours ago  Exited (0) 18 hours ago        happy_lalande     
ls
7634024ee0bf eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          18 hours ago  Exited (0) 18 hours ago        insane_mclean     
exit
14034a9720cb eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          18 hours ago  Exited (0) 18 hours ago        naughty_lumiere   
 
ca90954628db eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          19 hours ago  Exited (130) 18 hours ago      sick_hawking       
docker ps   # current running processes
8bbdcb7c339f eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          19 hours ago   Exited (0) 19 hours ago        modest_davinci     
docker ps -a # show all processes including closed
e8e24f80f0dd aaa75e64ddf0                                  "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago      berserk_hodgkin   
docker restart c85850ed0e13
d41959e0eb55 aaa75e64ddf0                                  "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago      jovial_curie       
docker ps   # container c85850ed0e13 is running
b408c0e2805b aaa75e64ddf0                                  "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago      lonely_tesla       
docker attach c85850ed0e13 # log into the system
72a551e4b492 ouruser/sinatra:v2                            "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago        jolly_meitner     
75fd6cc4658b training/sinatra:latest                        "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago        evil_yalow         
cc8886f5a02e training/sinatra:latest                        "/bin/bash"          5 weeks ago    Exited (130) 5 weeks ago      elegant_curie     
0585e4f5fecd eddelbuettel/docker-ubuntu-r:add-r-devel-san  "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago        elated_euclid     
brb@brbweb4:~/Downloads$
</pre>


When we want to delete a container, we use the container's '''CONTAINER ID''' or '''NAME''' (last column output from docker ps -a). But when we want to delete an image, we use the image's '''REPOSITORY''' or '''IMAGE ID''' (2nd column output from docker images)
ls /home
<pre>
exit
$ sudo docker rm thirsty_engelbart  # iman/touch
$ sudo docker rm dc9e82f2c00a      # eddelbuettel/docker-ubuntu-r:add-r-devel-san
$ sudo docker ps -a  # check to see the container is gone now


$ sudo docker rmi 6e0f5644b2fd
docker ps -a
$ sudo docker rmi iman/touch
docker rm c85850ed0e13 # delete the container
$ sudo docker images  # check to see the images are gone now
</pre>
</pre>
 
Note: Following the [http://askubuntu.com/questions/505506/docker-how-to-get-bash-ssh-inside-runned-container-run-d discussion], using '''attach''' can only launch one instance of shell. If we use '''exec''', we can launch multiple instances.
=== Command line interface, CLI ===
https://docs.docker.com/engine/reference/commandline/cli/ Docker command line
<pre>
<pre>
$ docker
sudo docker exec -i -t c85850ed0e13 bash #by ID
or
$ sudo docker exec -i -t loving_heisenberg bash #by Name
</pre>


Usage: docker COMMAND
== docker pull ==
https://docs.docker.com/engine/reference/commandline/pull/


A self-sufficient runtime for containers
<syntaxhighlight lang='bash'>
$ docker pull ubuntu:zesty
$ docker run -ti --rm ubuntu:zesty /bin/bash
# lsb_release -a       
bash: lsb_release: command not found
# cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=17.04
DISTRIB_CODENAME=zesty
DISTRIB_DESCRIPTION="Ubuntu 17.04"
NAME="Ubuntu"
VERSION="17.04 (Zesty Zapus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 17.04"
VERSION_ID="17.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=zesty
UBUNTU_CODENAME=zesty
</syntaxhighlight>


Options:
=== Update/upgrade images ===
      --config string      Location of client config files (default "/home/brb/.docker")
* I have an image called 'rocker/tidyverse:latest' that was pulled sometime ago. I ran ''docker pull rocker/tidyverse:latest' again. It will pull the latest image. The old image was not deleted and it has a new tag '''<none>'''.
  -D, --debug              Enable debug mode
* [https://success.docker.com/article/how-to-remove-a-signed-image-with-a-none-tag How to remove a signed image with a <none> tag]
  -H, --host list          Daemon socket(s) to connect to
* Same thing happened today. I run ''docker pull r-base'' to upgrade my r-base from v3.6.3 to v4.0.0. After the upgrade, the old image has a tag '''<none>'''. I can use '''docker rmi''' command to remove the <none> image.
  -l, --log-level string  Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
* [https://bytefreaks.net/applications/docker/how-to-update-all-pulled-docker-images-that-are-tagged-as-latest How to update all pulled Docker images that are tagged as latest]
      --tls                Use TLS; implied by --tlsverify
* [https://vsupalov.com/docker-latest-tag/ What's Wrong With The Docker :latest Tag?] '''Do not run any container with the latest tag.'''
      --tlscacert string  Trust certs signed only by this CA (default "/home/brb/.docker/ca.pem")
* [https://www.reddit.com/r/docker/comments/vjx9ct/how_to_upgrade_container_properly/ How to upgrade container properly?]  "docker-compose pull" to update all your service and "docker-compose up -d" to start them all. docker swarm is even better because you can achieve zero downtme rolling upgrades.
      --tlscert string    Path to TLS certificate file (default "/home/brb/.docker/cert.pem")
      --tlskey string      Path to TLS key file (default "/home/brb/.docker/key.pem")
      --tlsverify          Use TLS and verify the remote
  -v, --version            Print version information and quit


Management Commands:
=== <none>:<none> images ===
  config      Manage Docker configs
* [http://www.projectatomic.io/blog/2015/07/what-are-docker-none-none-images/ What are Docker <none>:<none> images? ]
  container  Manage containers
* [https://docs.docker.com/engine/reference/commandline/images/#filtering docker images]
  image      Manage images
  network    Manage networks
  node        Manage Swarm nodes
  plugin      Manage plugins
  secret      Manage Docker secrets
  service    Manage services
  swarm      Manage Swarm
  system      Manage Docker
  trust      Manage trust on Docker images
  volume      Manage volumes


Commands:
== Exit/detach from a container without stopping it ==
  attach      Attach local standard input, output, and error streams to a running container
<syntaxhighlight lang='bash'>
  build      Build an image from a Dockerfile
$ docker container run -it ubuntu:latest /bin/bash
  commit      Create a new image from a container's changes
# Ctrl+p, Ctrl+q to exit the container without terminating it
  cp          Copy files/folders between a container and the local filesystem
$ docker ps -a # showing the container 70c5aceb5512 is running in the background
  create      Create a new container
 
  diff        Inspect changes to files or directories on a container's filesystem
# You can reattach your terminal to it with the "docker container exec" command
  events      Get real time events from the server
$ docker container exec -it 70c5aceb5512 bash
  exec        Run a command in a running container
</syntaxhighlight>
  export      Export a container's filesystem as a tar archive
 
  history    Show the history of an image
== How to start a stopped Docker container with a different command ==
  images      List images
[https://stackoverflow.com/a/39329138 How to start a stopped Docker container with a different command?]
  import      Import the contents from a tarball to create a filesystem image
 
  info        Display system-wide information
== Clean shutdown DOCKER containers before reboot ==
  inspect    Return low-level information on Docker objects
* [https://forum.openmediavault.org/index.php?thread/22012-clean-shutdown-docker-containers-before-reboot-or-shutdown-omv/ Clean shutdown DOCKER containers before reboot or shutdown OMV] '''systemctl stop docker'''
  kill        Kill one or more running containers
* [https://linuxhandbook.com/docker-stop-container/ How to Stop Docker Containers] '''docker ps -q | xargs docker stop'''
  load        Load an image from a tar archive or STDIN
 
  login      Log in to a Docker registry
== Dockerizing Applications/Detached mode ==
  logout      Log out from a Docker registry
<pre>
  logs        Fetch the logs of a container
$ sudo docker run -d --name insane_babbage ubuntu:14.04 /bin/sh -c "while true; do echo hello world; sleep 1; done"
  pause      Pause all processes within one or more containers
$ sudo docker ps -l
  port        List port mappings or a specific mapping for the container
$ sudo docker logs insane_babbage
  ps          List containers
$ sudo docker stop insane_babbage
  pull        Pull an image or a repository from a registry
$ sudo docker ps
  push        Push an image or a repository to a registry
  rename      Rename a container
  restart    Restart one or more containers
  rm          Remove one or more containers
  rmi        Remove one or more images
  run        Run a command in a new container
  save        Save one or more images to a tar archive (streamed to STDOUT by default)
  search      Search the Docker Hub for images
  start      Start one or more stopped containers
  stats      Display a live stream of container(s) resource usage statistics
  stop        Stop one or more running containers
  tag        Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
  top        Display the running processes of a container
  unpause    Unpause all processes within one or more containers
  update      Update configuration of one or more containers
  version    Show the Docker version information
  wait        Block until one or more containers stop, then print their exit codes
 
Run 'docker COMMAND --help' for more information on a command.
</pre>
</pre>
The -d flag tells Docker to run the container and put it in the background, to daemonize it.
According to https://docs.docker.com/engine/reference/run/#detached-vs-foreground, 
'''containers started in detached mode exit when the root process used to run the container exits, unless you also specify the --rm option. If you use -d with --rm, the container is removed when it is stopped, exits or when the daemon exits, whichever happens first.'''
=== Automatically restart after reboot ===
https://stackoverflow.com/questions/18786054/how-to-auto-restart-a-docker-container-after-a-reboot-in-coreos
Add a '''--restart=always''' parameter. It will always restart a stopped container unless it has been explicitly stopped, such as via a "docker container stop" command. See the following
* https://docs.docker.com/engine/reference/commandline/run/#restart-policies-restart
* https://docs.docker.com/engine/admin/start-containers-automatically/#restart-policy-details


=== Version, system information ===
Docker version
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
$ docker version
$ docker run -d --restart always myCustomeDocker
Client:
Version:          18.06.1-ce
API version:      1.38
Go version:        go1.10.3
Git commit:        e68fc7a
Built:            Tue Aug 21 17:24:51 2018
OS/Arch:          linux/amd64
Experimental:      false


Server:
$ docker container run --name neverdie -it --restart always ubuntu /bin/bash
Engine:
# exit
  Version:          18.06.1-ce
$ docker ps -a  # the container is still ther
  API version:      1.38 (minimum version 1.12)
$ docker stop neverdie
  Go version:      go1.10.3
$ docker ps -a
  Git commit:      e68fc7a
  Built:            Tue Aug 21 17:23:15 2018
  OS/Arch:          linux/amd64
  Experimental:    false
</syntaxhighlight>
</syntaxhighlight>


System information.
== Working with Containers ==
* what mode the Docker engine is operating in (swarm mode or not)
<pre>
* what storage drive is used for the union filesystem
$ sudo docker run -i -t ubuntu /bin/bash
* what version of the Linux kernel we have on our host
$ sudo docker version
* et al
$ sudo docker
<syntaxhighlight lang='bash'>
$ sudo docker attach --help
$ docker system info
</pre>
Containers: 2
 
Running: 0
=== Environment variables ===
Paused: 0
* [https://www.baeldung.com/ops/docker-container-environment-variables Passing Environment Variables to Docker Containers]
Stopped: 2
* [https://docs.docker.com/compose/environment-variables/ Environment variables in Compose]
Images: 10
* An example: [https://github.com/tcardonne/docker-github-runner Docker github runner]
Server Version: 18.06.1-ce
 
Storage Driver: overlay2
=== Alpine image ===
Backing Filesystem: extfs
* [https://www.makeuseof.com/alpine-linux-explained/ Alpine Linux: A Breath of Fresh Mountain Air for Linux Experts]
Supports d_type: true
* [https://docs.docker.com/samples/library/alpine/ A minimal Docker image based on Alpine Linux with a complete package index and only 5 MB in size!]
Native Overlay Diff: true
* [http://containertutorials.com/alpine/get_started.html Container Tutorials > Getting Started with Alpine]
Logging Driver: json-file
* [https://nickjanetakis.com/blog/the-3-biggest-wins-when-using-alpine-as-a-base-docker-image The 3 Biggest Wins When Using Alpine as a Base Docker Image]
Cgroup Driver: cgroupfs
* [https://www.cyberciti.biz/faq/10-alpine-linux-apk-command-examples/ 10 Alpine Linux apk Command Examples]
Plugins:
: <syntaxhighlight lang='bash'>
Volume: local
apk add htop
Network: bridge host macvlan null overlay
</syntaxhighlight>
Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
 
Swarm: inactive
=== Running a Web Application ===
Runtimes: runc
<pre>
Default Runtime: runc
$ sudo docker run -d -P training/webapp python app.py
Init Binary: docker-init
</pre>
containerd version: 468a545b9edcd5932818eb9de8e72413e616e86e
 
runc version: 69663f0bd4b60df09991c08812a60108003fa340
Alpine linux is 6MB. It is a good OS to run a web application. See the demo [https://youtu.be/BFKNwr_wllc here].
init version: fec3683
 
Security Options:
=== Viewing our Web Application Container ===
apparmor
<pre>
seccomp
$ sudo docker ps -l
  Profile: default
$ sudo docker run -d -p 5000:5000 training/webapp python app.py
Kernel Version: 4.15.0-33-generic
</pre>
Operating System: Ubuntu 18.04.1 LTS
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 7.674GiB
Name: t420s
ID: VLWB:6BN3:U7KB:L4T4:GQIB:54F3:YZKJ:PAIR:HEUM:UQIC:XLZU:3IFJ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false


WARNING: No swap limit support
=== Check container status (docker status) - CPU, Memory usage ===
</syntaxhighlight>
<ul>
<li>[https://www.cloudytuts.com/tutorials/docker/how-to-check-memory-and-cpu-utilization-of-docker-container/ How to Check Memory and CPU Utilization of Docker Container]
<pre>
docker stats
</pre>
<li>[https://github.com/ColinFay/dockerstats docker stats]
</ul>


=== List resource consumption ===
=== Container networking===
<ul>
<li>https://docs.docker.com/network/
<li>[https://docs.docker.com/network/network-tutorial-standalone/#use-user-defined-bridge-networks Use user-defined bridge networks]
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
$ docker system df
$ docker network create MyNewNetworkName
TYPE               TOTAL              ACTIVE             SIZE               RECLAIMABLE
$ docker network ls
Images              10                  2                  2.58GB              1.519GB (58%)
NETWORK ID          NAME               DRIVER              SCOPE
Containers          2                  0                  304B                304B (100%)
abae0010bf2c        MyNewNetworkName    bridge             local
Local Volumes      2                  0                  314.7MB            314.7MB (100%)
bf4e73473028        bridge              bridge              local
Build Cache        0                  0                  0B                  0B
7dac0804bc33        host                host                local
dbe7f0daef6d        none               null                local
$ docker network remove MyNewNetworkName
# OR docker network rm MyNewNetworkName
</syntaxhighlight>
<li>https://youtu.be/Ox5mZBwc92E
<li>Use '''dig''' to find out the IP and run DNS query. [https://jvns.ca/blog/2021/01/04/docker-compose-is-nice/ Docker Compose: a nice way to set up a dev environment]
<li>[https://dev.to/leandronsp/mastering-the-docker-networking-2h57 Mastering the Docker networking]
</ul>
 
=== [https://docs.docker.com/network/host/ Host network] ===
If you use the '''host''' network driver for a container, that container’s network stack is not isolated from the Docker host. For instance, if you run a container which binds to port 80 and you use host networking, the container’s application will be available on port 80 on the host’s IP address.


$ docker system df -v # more detailed information
=== ping, ifconfig and ip commands not found in Ubuntu container ===
# We can use the information to clean up our system
<syntaxhighlight lang='bash'>
apt update
apt install iputils-ping # ping
apt install net-tools    # ifconfig
apt install iproute2      # ip
</syntaxhighlight>
</syntaxhighlight>


== [https://www.youtube.com/watch?v=umJYDAYxZys A brief intro to docker virtualization] ==
=== Network Port Shortcut ===
<pre>
<pre>
docker search --help
$ sudo docker port nostalgic_morse 5000
docker search redis
</pre>
docker search -s 100 redis
 
docker pull --help
=== Access Ports on the Host from a Docker Container ===
docker pull ubuntu # download all versions of ubuntu
[https://www.cloudsavvyit.com/6940/how-to-access-ports-on-the-host-from-a-docker-container/ How to Access Ports on the Host from a Docker Container]
docker images    # available local container images
 
docker pull centos:latest
=== Multiple NICs ===
docker run --help
[https://www.reddit.com/r/docker/comments/vi2alw/containers_in_docker_to_use_public_ip_addresses/ containers in docker to use public ip addresses directly]
cat /etc/issue  # look at the current distr name before running docker
docker run -it centos:latest /bin/bash
                # create a container & execute as a sudo


cat /etc/redhat-release
=== Viewing the Web Application's Logs ===
yum
<pre>
cd /home
$ sudo docker logs -f nostalgic_morse
touch temp.txt
</pre>
ls
exit
 
docker ps  # current running processes
docker ps -a # show all processes including closed
docker restart c85850ed0e13
docker ps  # container c85850ed0e13 is running
docker attach c85850ed0e13 # log into the system


ls /home
=== Clear Logs of Running Docker Containers ===
exit
[https://www.howtogeek.com/devops/how-to-clear-logs-of-running-docker-containers/ How to Clear Logs of Running Docker Containers]


docker ps -a
=== Looking at our Web Application Container's processes ===
docker rm c85850ed0e13 # delete the container
</pre>
Note: Following the [http://askubuntu.com/questions/505506/docker-how-to-get-bash-ssh-inside-runned-container-run-d discussion], using '''attach''' can only launch one instance of shell. If we use '''exec''', we can launch multiple instances.
<pre>
<pre>
sudo docker exec -i -t c85850ed0e13 bash #by ID
$ sudo docker top nostalgic_morse
or
$ sudo docker exec -i -t loving_heisenberg bash #by Name
</pre>
</pre>


== docker pull ==
=== Inspecting our Web Application Container ===
https://docs.docker.com/engine/reference/commandline/pull/
<syntaxhighlight lang='bash'>
$ sudo docker inspect nostalgic_morse
</syntaxhighlight>


=== Obtain the container's IP address, log into a running server ===
PS. '''Portainer''' web interface can show the IP addresses.
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
$ docker pull ubuntu:zesty
$ docker inspect <container id> | grep "IPAddress"
$ docker run -ti --rm ubuntu:zesty /bin/bash
# lsb_release -a       
bash: lsb_release: command not found
# cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=17.04
DISTRIB_CODENAME=zesty
DISTRIB_DESCRIPTION="Ubuntu 17.04"
NAME="Ubuntu"
VERSION="17.04 (Zesty Zapus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 17.04"
VERSION_ID="17.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=zesty
UBUNTU_CODENAME=zesty
</syntaxhighlight>
</syntaxhighlight>


=== Update/upgrade images ===
We don't need the IP address if we just want to log into a running server,
* I have an image called 'rocker/tidyverse:latest' that was pulled sometime ago. I ran ''docker pull rocker/tidyverse:latest' again. It will pull the latest image. The old image was not deleted and it has a new tag '''<none>'''.
<syntaxhighlight lang='bash'>
* [https://success.docker.com/article/how-to-remove-a-signed-image-with-a-none-tag How to remove a signed image with a <none> tag]
$ docker exec -it <contianer id> bash
* Same thing happened today. I run ''docker pull r-base'' to upgrade my r-base from v3.6.3 to v4.0.0. After the upgrade, the old image has a tag '''<none>'''. I can use '''docker rmi''' command to remove the <none> image.
</syntaxhighlight>
* [https://bytefreaks.net/applications/docker/how-to-update-all-pulled-docker-images-that-are-tagged-as-latest How to update all pulled Docker images that are tagged as latest]
 
* [https://vsupalov.com/docker-latest-tag/ What's Wrong With The Docker :latest Tag?] '''Do not run any container with the latest tag.'''
=== How to Secure Docker’s TCP Socket ===
[https://www.cloudsavvyit.com/15079/how-to-secure-dockers-tcp-socket-with-tls/ How to Secure Docker’s TCP Socket with TLS]


=== <none>:<none> images ===
=== docker attach ===
* [http://www.projectatomic.io/blog/2015/07/what-are-docker-none-none-images/ What are Docker <none>:<none> images? ]
Suppose I run ''docker run -it --user rstudio bioconductor/bioconductor_docker:devel R'' and I use ''q()'' to quit the container. The container is still there. To re-enter the R in the container, I use
* [https://docs.docker.com/engine/reference/commandline/images/#filtering docker images]
<pre>
docker start XXXXXXXX    # restart it in the background
docker attach XXXXXXXX  # reattach the terminal & stdin
</pre>
If we want the latest created container, then we use
<pre>
docker start `docker ps -q -l` && docker attach `docker ps -q -l`
</pre>


== Exit/detach from a container without stopping it ==
=== docker exec: SSH into a running container ===
<syntaxhighlight lang='bash'>
Run a command in a running container
$ docker container run -it ubuntu:latest /bin/bash
# Ctrl+p, Ctrl+q to exit the container without terminating it
$ docker ps -a # showing the container 70c5aceb5512 is running in the background


# You can reattach your terminal to it with the "docker container exec" command
* [https://docs.docker.com/engine/reference/commandline/exec/ Usage]: <syntaxhighlight lang='bash'>
$ docker container exec -it 70c5aceb5512 bash
docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
</syntaxhighlight>
</syntaxhighlight>
* Examples: <syntaxhighlight lang='bash'>
$ docker exec -d ubuntu_bash touch /tmp/execWorks # do st in the background


== How to start a stopped Docker container with a different command ==
$ docker exec -it ubuntu_bash bash
[https://stackoverflow.com/a/39329138 How to start a stopped Docker container with a different command?]


== Clean shutdown DOCKER containers before reboot ==
$ docker exec -it -e VAR=1 ubuntu_bash bash # set an environment variable
* [https://forum.openmediavault.org/index.php?thread/22012-clean-shutdown-docker-containers-before-reboot-or-shutdown-omv/ Clean shutdown DOCKER containers before reboot or shutdown OMV] '''systemctl stop docker'''
* [https://linuxhandbook.com/docker-stop-container/ How to Stop Docker Containers] '''docker ps -q | xargs docker stop'''


== Dockerizing Applications/Detached mode ==
$ docker exec -it ubuntu_bash pwd
<pre>
$ docker exec -it -w /root ubuntu_bash pwd # change the working directory
$ sudo docker run -d --name insane_babbage ubuntu:14.04 /bin/sh -c "while true; do echo hello world; sleep 1; done"
</syntaxhighlight>
$ sudo docker ps -l
* [https://www.cloudsavvyit.com/14541/how-to-run-a-command-on-a-running-docker-container/ How to Run a Command on a Running Docker Container]
$ sudo docker logs insane_babbage
$ sudo docker stop insane_babbage
$ sudo docker ps
</pre>
The -d flag tells Docker to run the container and put it in the background, to daemonize it.


According to https://docs.docker.com/engine/reference/run/#detached-vs-foreground, 
=== docker cp ===
'''containers started in detached mode exit when the root process used to run the container exits, unless you also specify the --rm option. If you use -d with --rm, the container is removed when it is stopped, exits or when the daemon exits, whichever happens first.'''
* https://docs.docker.com/engine/reference/commandline/cp/
* https://linuxhandbook.com/docker-cp-example/


=== Automatically restart after reboot ===
Copy files/folders between a container and the local filesystem.
https://stackoverflow.com/questions/18786054/how-to-auto-restart-a-docker-container-after-a-reboot-in-coreos


Add a '''--restart=always''' parameter. It will always restart a stopped container unless it has been explicitly stopped, such as via a "docker container stop" command. See the following
=== Restart an exited Container ===
* https://docs.docker.com/engine/reference/commandline/run/#restart-policies-restart
* https://docs.docker.com/engine/reference/commandline/start/
* https://docs.docker.com/engine/admin/start-containers-automatically/#restart-policy-details
* https://www.linuxnix.com/docker-start-exited-container/
<pre>
$ docker start nostalgic_morse
OR
$ docker restart nostalgic_morse
</pre>
For an interactive container, use '''docker start -ai CONTAINER''' which is equal to run "docker start CONTAINER" and "docker attach CONTAINER".


<syntaxhighlight lang='bash'>
=== Rename a container ===
$ docker run -d --restart always myCustomeDocker
[https://docs.docker.com/engine/reference/commandline/container_rename/ docker container rename]
 
$ docker container run --name neverdie -it --restart always ubuntu /bin/bash
# exit
$ docker ps -a  # the container is still ther
$ docker stop neverdie
$ docker ps -a
</syntaxhighlight>
 
== Working with Containers ==
<pre>
<pre>
$ sudo docker run -i -t ubuntu /bin/bash
docker container rename CONTAINER NEW_NAME
$ sudo docker version
$ sudo docker
$ sudo docker attach --help
</pre>
</pre>


=== Environment variables ===
=== Inspect container images and their metadata ===
* [https://www.baeldung.com/ops/docker-container-environment-variables Passing Environment Variables to Docker Containers]
* [https://www.cloudsavvyit.com/14663/how-to-inspect-a-docker-images-content-without-starting-a-container/ How to Inspect a Docker Image’s Content Without Starting a Container]
* [https://docs.docker.com/compose/environment-variables/ Environment variables in Compose]
* [https://microbadger.com/images/rocker/r-base MicroBadger]
* An example: [https://github.com/tcardonne/docker-github-runner Docker github runner]


=== Alpine image ===
=== Know the container size ===
* [https://www.makeuseof.com/alpine-linux-explained/ Alpine Linux: A Breath of Fresh Mountain Air for Linux Experts]
<syntaxhighlight lang='bash'>
* [https://docs.docker.com/samples/library/alpine/ A minimal Docker image based on Alpine Linux with a complete package index and only 5 MB in size!]
docker ps -s
* [http://containertutorials.com/alpine/get_started.html Container Tutorials > Getting Started with Alpine]
</syntaxhighlight>
* [https://nickjanetakis.com/blog/the-3-biggest-wins-when-using-alpine-as-a-base-docker-image The 3 Biggest Wins When Using Alpine as a Base Docker Image]
[https://github.com/docker/docker.github.io/issues/1520#issuecomment-305179362 Meaning of two sizes]
* [https://www.cyberciti.biz/faq/10-alpine-linux-apk-command-examples/ 10 Alpine Linux apk Command Examples]
* The "size" information shows the amount of data (on disk) that is used for the writable layer of each container
: <syntaxhighlight lang='bash'>
* The "virtual size" is the amount of disk-space used for the read-only image data used by the container.
apk add htop
 
=== Removing our Web Application Container ===
<syntaxhighlight lang='bash'>
$ sudo docker stop nostalgic_morse
$ sudo docker rm nostalgic_morse
</syntaxhighlight>
</syntaxhighlight>


=== Running a Web Application ===
Note: Always remember that deleting a container is final!
 
=== Dockerize an SSH service ===
https://docs.docker.com/engine/examples/running_ssh_service/#environment-variables
 
=== Remove old docker containers ===
[http://stackoverflow.com/questions/17236796/how-to-remove-old-docker-io-containers This post] on stackoverflow.com.
<pre>
<pre>
$ sudo docker run -d -P training/webapp python app.py
$ sudo docker ps -a | grep 'weeks ago' | awk '{print $1}' | xargs --no-run-if-empty sudo docker rm
</pre>
</pre>


Alpine linux is 6MB. It is a good OS to run a web application. See the demo [https://youtu.be/BFKNwr_wllc here].
Similarly to remove all exited containers
 
=== Viewing our Web Application Container ===
<pre>
<pre>
$ sudo docker ps -l
$ sudo docker ps -a | grep Exit | awk '{print $1}' | xargs sudo docker rm
$ sudo docker run -d -p 5000:5000 training/webapp python app.py
</pre>
</pre>


=== Check container status (docker status) - CPU, Mem usage ===
To kill/stop (not delete) all running containers
[https://github.com/ColinFay/dockerstats docker stats]
<pre>
$ sudo docker kill $(sudo docker ps -q)
</pre>


=== Container networking===
'''To delete all stopped containers'''
* https://docs.docker.com/network/
* [https://docs.docker.com/network/network-tutorial-standalone/#use-user-defined-bridge-networks Use user-defined bridge networks]
<syntaxhighlight lang='bash'>
$ docker network create MyNewNetworkName
$ docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
abae0010bf2c        MyNewNetworkName    bridge              local
bf4e73473028        bridge              bridge              local
7dac0804bc33        host                host                local
dbe7f0daef6d        none                null                local
$ docker network remove MyNewNetworkName
# OR docker network rm MyNewNetworkName
</syntaxhighlight>
* https://youtu.be/Ox5mZBwc92E
 
=== [https://docs.docker.com/network/host/ Host network] ===
If you use the '''host''' network driver for a container, that container’s network stack is not isolated from the Docker host. For instance, if you run a container which binds to port 80 and you use host networking, the container’s application will be available on port 80 on the host’s IP address.
 
=== ping, ifconfig and ip commands not found in Ubuntu container ===
<syntaxhighlight lang='bash'>
apt update
apt install iputils-ping  # ping
apt install net-tools    # ifconfig
apt install iproute2      # ip
</syntaxhighlight>
 
=== Network Port Shortcut ===
<pre>
<pre>
$ sudo docker port nostalgic_morse 5000
$ sudo docker rm $(sudo docker ps -a -q)
OR
$ sudo docker rm `sudo docker ps -a -q`
</pre>
</pre>


=== Access Ports on the Host from a Docker Container ===
It is also helpful to create bash aliases for these commands by editing ~/.bash_aliases file.
[https://www.cloudsavvyit.com/6940/how-to-access-ports-on-the-host-from-a-docker-container/ How to Access Ports on the Host from a Docker Container]
 
=== docker create vs docker run ===
https://stackoverflow.com/questions/37744961/docker-run-vs-create
 
'''docker create''' is similar to '''docker run -d''' except the container is never started.


=== Viewing the Web Application's Logs ===
=== Retrieve docker run command ===
https://stackoverflow.com/a/32774347. See the github page of [https://github.com/lavie/runlike runlike]. So it is better to put the docker run in a stack. Then for example the Portainer has an Editor tab to show the [https://docs.docker.com/compose/compose-file/ compose file].
<pre>
<pre>
$ sudo docker logs -f nostalgic_morse
docker run --rm -v /var/run/docker.sock:/var/run/docker.sock \
    assaflavie/runlike -p CONTAINER_NAME
</pre>
</pre>
The '''-p''' option splits the output into pretty lines.
=== docker run -it and -d together ===
* [https://stackoverflow.com/a/41918607 Practically, what is the difference between docker run -dit(-itd) vs docker run -d?]
* [https://github.com/docker/docker.github.io/issues/10632 "docker run -dit" vs "docker run -d" #10632]
=== How to Modify the Configuration of Running Docker Containers ===
[https://www.cloudsavvyit.com/15254/how-to-modify-the-configuration-of-running-docker-containers/ How to Modify the Configuration of Running Docker Containers]
== Volume ==
* https://docs.docker.com/storage/volumes/
* [https://docs.docker.com/engine/reference/commandline/volume_create/ docker volume create] documentation
* If we try to mount an empty dir on the host to a non-empty dir (eg mediawiki/extensions) in a container, it will mess up.
* [https://www.melvinvivas.com/using-docker-data-volume-with-a-mysql-container/ Using Docker Data Volume with a MySQL container]
* [https://www.cloudsavvyit.com/7500/what-are-docker-volumes-and-how-do-you-use-them/ What Are Docker Volumes, and How Do You Use Them?]


=== Looking at our Web Application Container's processes ===
=== Examples of host's volume locations ===
<pre>
<pre>
$ sudo docker top nostalgic_morse
/home/$USER/docker/$PROJECT/$SUB-DIRECTORY
</pre>
</pre>


=== Inspecting our Web Application Container ===
=== Two ways to achieve persistent data ===
* [https://codeblog.dotsandbrackets.com/persistent-data-docker-volumes/ Persistent data in Docker volumes]
* [https://www.cloudsavvyit.com/3588/how-to-deal-with-docker-container-persistence-and-storage/ How to Deal with Docker Container Persistence and Storage]. Docker has two ways to achieve persistence: '''volume mounts''', and '''bind mounts'''.
 
=== Inspect the 'Mountpoint' of a volume ===
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
$ sudo docker inspect nostalgic_morse
$ docker volume create crv
</syntaxhighlight>
$ docker volume ls


=== Obtain the container's IP address, log into a running server ===
$ docker run -d \
PS. '''Portainer''' web interface can show the IP addresses.  
    --name mycloud \
<syntaxhighlight lang='bash'>
    -p 81:80 \
$ docker inspect <container id> | grep "IPAddress"
    -v apps:/var/www/html/custom_apps \
    nextcloud
 
# docker inspect is not quite useful. It does not show how the volume was created
# But we can examine (ls, du, ...) the directory contents
$ docker inspect apps 
[
    {
        "CreatedAt": "2018-10-23T09:41:52-04:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/apps/_data",
        "Name": "apps",
        "Options": null,
        "Scope": "local"
    }
]
</syntaxhighlight>
</syntaxhighlight>


We don't need the IP address if we just want to log into a running server,
=== Remove an an unnamed volume ===
If you created an unnamed volume, it can be deleted at the same time as the container with the -v flag. Note that this only works with unnamed volumes.
 
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
$ docker exec -it <contianer id> bash
docker rm -v container_name
</syntaxhighlight>
</syntaxhighlight>


=== How to Secure Docker’s TCP Socket ===
If the volume is named, it stays present. To remove a named volume, use '''docker volume rm volume_name''' .
[https://www.cloudsavvyit.com/15079/how-to-secure-dockers-tcp-socket-with-tls/ How to Secure Docker’s TCP Socket with TLS]


=== docker attach ===
=== [https://docs.docker.com/storage/volumes/#start-a-container-with-a-volume Start a container with a volume] ===
Suppose I run ''docker run -it --user rstudio bioconductor/bioconductor_docker:devel R'' and I use ''q()'' to quit the container. The container is still there. To re-enter the R in the container, I use
{| class="wikitable"
<pre>
! --mount
docker start XXXXXXXX    # restart it in the background
! -v
docker attach XXXXXXXX  # reattach the terminal & stdin
|-
</pre>
| docker run -d \
If we want the latest created container, then we use
--name devtest \ <br/>
<pre>
--mount source=myvol2,target=/app \  <br/>
docker start `docker ps -q -l` && docker attach `docker ps -q -l`
nginx:latest
</pre>
| docker run -d \
--name devtest \  <br/>
-v myvol2:/app \  <br/>
nginx:latext
|}
Note
* '''target''' in "--mount" can be replaced by '''destination''' or '''dst'''.
* To use a read-only volume, add the ''',readonly''' option in "--mount" or the ''':ro''' option in "-v".
* We cannot use "~/" to represent a local directory under HOME. We have to specify a full path in '''docker run'''.


=== docker exec: SSH into a running container ===
=== A simple example ===
Run a command in a running container
From the book "Learn Docerk -Fundamentals of Docker 18.x". Chap 5. Data Volumes and System Management > Creating and mounting data volumes.


* [https://docs.docker.com/engine/reference/commandline/exec/ Usage]: <syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
# Create a volume
</syntaxhighlight>
docker volume create my-data
* Examples: <syntaxhighlight lang='bash'>
docker volume inspect my-data
$ docker exec -d ubuntu_bash touch /tmp/execWorks # do st in the background
# The host folder can be found in the output under 'Mountpoint'
# In my case,
#        "Mountpoint": "/var/lib/docker/volumes/my-data/_data",


$ docker exec -it ubuntu_bash bash
# Mount a volume into a container
docker run --name test -it -v my-data:/data alpine /bin/sh
# cd /data
# echo 'some data' > data.txt
# echo 'more data' > data2.txt
# exit
docker inspect my-data
sudo ls /var/lib/docker/volumes/my-data/_data
# We can even try to output the content of say, the second file:
sudo cat /var/lib/docker/volumes/my-data/_data/data2.txt
# We can create a new file in this folder from the host and then use the volume with another container
echo "the file is created on host" > sudo tee /var/lib/docker/volumes/my-data/_data/host-data
# Let's delete the test container and run another one
docker rm test


$ docker exec -it -e VAR=1 ubuntu_bash bash # set an environment variable
# This time we are mounting our volume to a different container folder
docker run --name test2 -it -v my-data:/app/data centos:7 /bin/bash
# We are able to see three files:
# ls /app/data


$ docker exec -it ubuntu_bash pwd
# Remove volumes
$ docker exec -it -w /root ubuntu_bash pwd # change the working directory
docker volume rm my-data # Or
docker volume rm $(docker volume ls -q)
 
# Remove all running containers to clean up the system,
docker rm -f $(docker ls -aq)
</syntaxhighlight>
</syntaxhighlight>
* [https://www.cloudsavvyit.com/14541/how-to-run-a-command-on-a-running-docker-container/ How to Run a Command on a Running Docker Container]


=== docker cp ===
=== Sharing data between containers ===
* https://docs.docker.com/engine/reference/commandline/cp/
[https://www.cloudsavvyit.com/15112/how-to-share-data-between-docker-containers/ How to Share Data Between Docker Containers]
* https://linuxhandbook.com/docker-cp-example/  


Copy files/folders between a container and the local filesystem.
<syntaxhighlight lang='bash'>
docker run -it --name writer -v shared-data:/data alpine /bin/sh
# create a file inside it
# echo 'my sample file' > /data/sample.txt
# exit
docker run -it --name reader -v shared-data:/app/data:ro ubuntu:17.04 /bin/bash
# ls -l /app/data
</syntaxhighlight>


=== Restart an exited Container ===
=== Using host volumes ===
* https://docs.docker.com/engine/reference/commandline/start/
Use volumes that mount a specific host folder
* https://www.linuxnix.com/docker-start-exited-container/
* It may be possible for the "docker volume" command to mount a local directory to a volume. See [https://docs.docker.com/engine/reference/commandline/volume_create/#examples examples] in the "docker volume create" documentation.
<pre>
* Specifying a directory name instead of giving a volume name in the "docker run" 's '''-v''' option
$ docker start nostalgic_morse
* Since we are specifying a directory name instead of letting docker to create a new volume, "docker volume ls" will not getting a new volume
OR
<syntaxhighlight lang='bash'>
$ docker restart nostalgic_morse
docker run -it --name test -v $(pwd)/src:/app/src alpine /bin/sh
</pre>
 
For an interactive container, use '''docker start -ai CONTAINER''' which is equal to run "docker start CONTAINER" and "docker attach CONTAINER".
# Make a sample to demonstrate how that works
mkdir ~/my-web; cd ~/my-web
echo "<h1>My website</h1>" > index.html


=== Rename a container ===
# Create 'Dockerfile'
[https://docs.docker.com/engine/reference/commandline/container_rename/ docker container rename]
echo -e 'FROM nginx:alpine
<pre>
COPY . /usr/share/nginx/html' > Dockerfile
docker container rename CONTAINER NEW_NAME
</pre>


=== Inspect container images and their metadata ===
docker image build -t my-website:1.0 .
* [https://www.cloudsavvyit.com/14663/how-to-inspect-a-docker-images-content-without-starting-a-container/ How to Inspect a Docker Image’s Content Without Starting a Container]
docker run -d -p 8080:80 --name my-site my-website:1.0
* [https://microbadger.com/images/rocker/r-base MicroBadger]


=== Know the container size ===
# Open http://localhost:8080. It looks good
<syntaxhighlight lang='bash'>
# Now modify index.html and refresh the website. It does not refresh
docker ps -s
# Let's stop and rm the container and rebuild using a volume
docker rm -f my-site
docker run -d -v $(pwd):/usr/share/nginx/html \
  -p 8080:80 --name my-site my-website:1.0
# Now any changes on index.html will refresh on the website
</syntaxhighlight>
</syntaxhighlight>
[https://github.com/docker/docker.github.io/issues/1520#issuecomment-305179362 Meaning of two sizes]
* The "size" information shows the amount of data (on disk) that is used for the writable layer of each container
* The "virtual size" is the amount of disk-space used for the read-only image data used by the container.


=== Removing our Web Application Container ===
=== Define volumes in images ===
<syntaxhighlight lang='bash'>
A few samples of volume definition
$ sudo docker stop nostalgic_morse
$ sudo docker rm nostalgic_morse
</syntaxhighlight>
 
Note: Always remember that deleting a container is final!
 
=== Dockerize an SSH service ===
https://docs.docker.com/engine/examples/running_ssh_service/#environment-variables
 
=== Remove old docker containers ===
[http://stackoverflow.com/questions/17236796/how-to-remove-old-docker-io-containers This post] on stackoverflow.com.
<pre>
<pre>
$ sudo docker ps -a | grep 'weeks ago' | awk '{print $1}' | xargs --no-run-if-empty sudo docker rm
VOLUME /app/data
VOLUME /app/data, /app/profiles, /app/config
VOLUME {"/app/data", "/app/profiles", "/app/config"]
</pre>
</pre>
The first line defines a single volume to be mounted at ''/app/data''.


Similarly to remove all exited containers
We can use the ''docker image inspect'' command to get information about the volumes defined in the Dockerfile.
<pre>
<syntaxhighlight lang='bash'>
$ sudo docker ps -a | grep Exit | awk '{print $1}' | xargs sudo docker rm
docker image pull mongo:3.7
</pre>
docker image inspect --format='{{json .ContainerConfig.Volumes}}' \
      mongo:3.7 | jq
# {
#  "/data/configdb": {},
#  "/data/db": {}
# }


To kill/stop (not delete) all running containers
# now run an instance of MongoDB and inspect the volume information
<pre>
docker run --name my-mongo -d mongo:3.7
$ sudo docker kill $(sudo docker ps -q)
docker inspect --format '{{json .Mounts}}' my-mongo | jq
</pre>
# [
#  {
#    "Type": "volume",
#    "Name": "535e0138b9a32e89f71380e9e73bb0de64ce0d1cad78fcda0ec1d49e11d76d7a",
#    "Source": "/var/lib/docker/volumes/535e0138b9a32e89f71380e9e73bb0de64ce0d1.../_data",
#    "Destination": "/data/configdb",
#    "Driver": "local",
#    "Mode": "",
#    "RW": true,
#    "Propagation": ""
#  },
#  {
#    "Type": "volume",
# SKIP
</syntaxhighlight>


'''To delete all stopped containers'''
=== Differences between VOLUME and '-v|--volume' ===
<pre>
https://stackoverflow.com/a/25312719
$ sudo docker rm $(sudo docker ps -a -q)
OR
$ sudo docker rm `sudo docker ps -a -q`
</pre>


It is also helpful to create bash aliases for these commands by editing ~/.bash_aliases file.
=== Container Memory Limits, Setting Available CPUs, Allocating memory and CPU ===
 
* [https://medium.com/@nitesh.turaga/how-i-use-bioconductor-with-docker-part-2-more-memory-faster-bioconductor-with-docker-fd7e69dce2bf How I use Bioconductor with Docker (part 2): More memory, faster Bioconductor with Docker]
=== docker create vs docker run ===
: <syntaxhighlight lang='bash'>
https://stackoverflow.com/questions/37744961/docker-run-vs-create
docker run \
    -rm \ ## Automatically remove the container when it exits
    --memory=6g \ ## memory limit
    --cpus=1.5 \ ## number of CPUs
    -v /shared/data-store:/home/rstudio/data \
    -v /shared/library-store:/usr/local/lib/R/host-site-library \
    -e PASSWORD=bioc \
    -p 8787:8787 \
        bioconductor/bioconductor_full:devel
</syntaxhighlight>
* [https://docs.docker.com/docker-for-mac/ Get started with Docker Desktop for Mac], [https://docs.docker.com/docker-for-windows/ Windows]
* [https://docs.docker.com/config/containers/resource_constraints/ Limit a container's resources]
* [https://blog.docker.com/2018/12/top-5-post-docker-container-java/ TOP 5 BLOG OF 2018: IMPROVED DOCKER CONTAINER INTEGRATION WITH JAVA 10]
* [https://www.jottr.org/2022/04/22/parallelly-1.31.1/ parallelly 1.31.1: Better at Inferring Number of CPU Cores with Cgroups and Linux Containers]
* [https://www.thorsten-hans.com/limit-memory-for-docker-containers Docker Container Memory Limits Explained]
* [https://www.howtogeek.com/devops/how-to-set-a-memory-limit-for-docker-containers/ How to Set a Memory Limit for Docker Containers]


'''docker create''' is similar to '''docker run -d''' except the container is never started.
== Work with container images ==
* https://docs.docker.com/userguide/dockerimages/


=== Retrieve docker run command ===
=== List images by size or name ===
https://stackoverflow.com/a/32774347. See the github page of [https://github.com/lavie/runlike runlike]. So it is better to put the docker run in a stack. Then for example the Portainer has an Editor tab to show the [https://docs.docker.com/compose/compose-file/ compose file].
<pre>
<pre>
docker run --rm -v /var/run/docker.sock:/var/run/docker.sock \
# by size
    assaflavie/runlike CONTAINER_NAME
docker images --format "{{.ID}}\t{{.Size}}\t{{.Repository}}" | sort -k 2 -h
 
# by name
docker images --format "{{.ID}}\t{{.Size}}\t{{.Repository}}" | sort -k 3
</pre>
</pre>


=== How to Modify the Configuration of Running Docker Containers ===
=== List specific columns ===
[https://www.cloudsavvyit.com/15254/how-to-modify-the-configuration-of-running-docker-containers/ How to Modify the Configuration of Running Docker Containers]
<pre>
docker images --format 'table {{.Repository}}\t{{.Tag}}\t{{.Size}}'
</pre>


== Volume ==
=== Create an image interactively using '''commit''' - Example 1 ===
* https://docs.docker.com/storage/volumes/
The example is from the book 'Learn Docker - Fundamentals of Docker 18.x'.
* [https://docs.docker.com/engine/reference/commandline/volume_create/ docker volume create] documentation
<syntaxhighlight lang='bash'>
* If we try to mount an empty dir on the host to a non-empty dir (eg mediawiki/extensions) in a container, it will mess up.
docker container run -it --name sample alpine /bin/sh
* [https://www.melvinvivas.com/using-docker-data-volume-with-a-mysql-container/ Using Docker Data Volume with a MySQL container]
# apk update && apk add iputils
* [https://www.cloudsavvyit.com/7500/what-are-docker-volumes-and-how-do-you-use-them/ What Are Docker Volumes, and How Do You Use Them?]
# ping 127.0.0.1
# exit
docker container ls -a | grep sample
docker container diff sample
</syntaxhighlight>
We can now use the ''docker container commit'' command to persist our modifications and create a new image from them
<syntaxhighlight lang='bash'>
docker container commit sample my-alpine
docker images ls
</syntaxhighlight>


=== Two ways to achieve persistent data ===
If we want to see how our custom image has been built, we can use the ''history'' command as follows:
* [https://codeblog.dotsandbrackets.com/persistent-data-docker-volumes/ Persistent data in Docker volumes]
* [https://www.cloudsavvyit.com/3588/how-to-deal-with-docker-container-persistence-and-storage/ How to Deal with Docker Container Persistence and Storage]. Docker has two ways to achieve persistence: '''volume mounts''', and '''bind mounts'''.
 
=== Inspect the 'Mountpoint' of a volume ===
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
$ docker volume create crv
docker image history my-alpine
$ docker volume ls
# IMAGE              CREATED              CREATED BY                                      SIZE    COMMENT
# 0f105057899b        About a minute ago  /bin/sh                                        1.55MB             
# 196d12cf6ab1        4 weeks ago          /bin/sh -c #(nop)  CMD ["/bin/sh"]              0B                 
# <missing>          4 weeks ago          /bin/sh -c #(nop) ADD file:25c10b1d1b41d46a1…  4.41MB
</syntaxhighlight>
The first layer in the preceding list is the one we just created by adding the iputils package.


$ docker run -d \
=== Create an image interactively using '''commit''' - Example 2 ===
    --name mycloud \
* [https://www.cloudsavvyit.com/15489/how-to-create-a-docker-image-from-a-running-container/ How to Create a Docker Image From a Running Container]. Commit messages are displayed when you use the '''docker history''' command to view the layers in an image.
    -p 81:80 \
* [http://www.techrepublic.com/article/how-to-commit-changes-to-a-docker-image/ How to commit changes to a docker image]
    -v apps:/var/www/html/custom_apps \
    nextcloud


# docker inspect is not quite useful. It does not show how the volume was created
<span style="color: red">Note that it is better/necessary to put the Dockerfile in an empty directory</span> to avoid the problem of taking a long time to build the image (''sending build context to Docker daemon ...GB '') since it will grab files from the current directory.
# But we can examine (ls, du, ...) the directory contents
$ docker inspect apps 
[
    {
        "CreatedAt": "2018-10-23T09:41:52-04:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/apps/_data",
        "Name": "apps",
        "Options": null,
        "Scope": "local"
    }
]
</syntaxhighlight>
 
=== Remove an an unnamed volume ===
If you created an unnamed volume, it can be deleted at the same time as the container with the -v flag. Note that this only works with unnamed volumes.


<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker rm -v container_name
sudo docker search sinatra
</syntaxhighlight>
sudo docker pull training/sinatra
sudo docker run -t -i training/sinatra /bin/bash
sudo docker commit -m="Added json gem" -a="Kate Smith" 0b2616b0e5a8 ouruser/sinatra:v2
sudo docker images


If the volume is named, it stays present. To remove a named volume, use '''docker volume rm volume_name''' .
mkdir sinatra
cd sinatra
touch Dockerfile
sudo docker build -t="ouruser/sinatra:v2" .
sudo docker push ouruser/sinatra
sudo docker rmi training/sinatra
</syntaxhighlight>


=== [https://docs.docker.com/storage/volumes/#start-a-container-with-a-volume Start a container with a volume] ===
* I get an error when I try to launch sinatra on my 32-bit ubuntu (Docker can only be installed through apt-get on 32-bit)
{| class="wikitable"
<pre>
! --mount
$ sudo docker run -t -i training/sinatra /bin/bash
! -v
2014/12/31 02:43:26 exec format error
|-
</pre>
| docker run -d \
--name devtest \ <br/>
--mount source=myvol2,target=/app \  <br/>
nginx:latest
| docker run -d \
--name devtest \  <br/>
-v myvol2:/app \  <br/>
nginx:latext
|}
Note
* '''target''' in "--mount" can be replaced by '''destination''' or '''dst'''.
* To use a read-only volume, add the ''',readonly''' option in "--mount" or the ''':ro''' option in "-v".
* We cannot use "~/" to represent a local directory under HOME. We have to specify a full path in '''docker run'''.
 
=== A simple example ===
From the book "Learn Docerk -Fundamentals of Docker 18.x". Chap 5. Data Volumes and System Management > Creating and mounting data volumes.


=== How to copy Docker images from one host to another without using a repository ===
https://stackoverflow.com/questions/23935141/how-to-copy-docker-images-from-one-host-to-another-without-using-a-repository
<syntaxhighlight lang='bash'>
docker save -o out.tar <image name>
# Or better to compress the file
docker save <docker image name> | gzip > out.tar.gz
</syntaxhighlight>
And restore
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
# Create a volume
docker load -i out.tar
docker volume create my-data
# Or decompress the file
docker volume inspect my-data
docker load < out.tar.gz
# The host folder can be found in the output under 'Mountpoint'
</syntaxhighlight>
# In my case,
#        "Mountpoint": "/var/lib/docker/volumes/my-data/_data",


# Mount a volume into a container
=== Docker Image Manifest ===
docker run --name test -it -v my-data:/data alpine /bin/sh
[https://www.cloudsavvyit.com/12330/what-is-a-docker-image-manifest/ What Is a Docker Image Manifest?]
# cd /data
# echo 'some data' > data.txt
# echo 'more data' > data2.txt
# exit
docker inspect my-data
sudo ls /var/lib/docker/volumes/my-data/_data
# We can even try to output the content of say, the second file:
sudo cat /var/lib/docker/volumes/my-data/_data/data2.txt
# We can create a new file in this folder from the host and then use the volume with another container
echo "the file is created on host" > sudo tee /var/lib/docker/volumes/my-data/_data/host-data
# Let's delete the test container and run another one
docker rm test


# This time we are mounting our volume to a different container folder
=== Resources allocated to a container using docker? ===
docker run --name test2 -it -v my-data:/app/data centos:7 /bin/bash
https://stackoverflow.com/questions/16084741/how-do-i-set-resources-allocated-to-a-container-using-docker
# We are able to see three files:
# ls /app/data


# Remove volumes
== hub.docker.com ==
docker volume rm my-data # Or
* Note that Dockerfile is optional on https://registry.hub.docker.com.
docker volume rm $(docker volume ls -q)
* For free account, we can have only [https://docs.docker.com/docker-hub/repos/ 1 free private repository]. If we want to create a new repository online, we can
 
: <syntaxhighlight lang='bash'>
# Remove all running containers to clean up the system,
docker tag local-image:tagname new-repo:tagname
docker rm -f $(docker ls -aq)
docker login
docker push new-repo:tagname
</syntaxhighlight>
* [https://stackoverflow.com/a/28349540 How to push a docker image to a private repository]
* [https://registry.hub.docker.com/repos/rocker/ rocker]. The Dockerfile is included there. Question: how to automatically build the image rather than uploading pre-built image binaries to Docker Hub?
* Search all repositories related to [https://registry.hub.docker.com/search?q=r&searchfield= R]
* [http://phusion.github.io/baseimage-docker/ baseimage-docker]. I can use ping command without special argument when I start phusion/baseimage.
: <syntaxhighlight lang='bash'>
docker pull phusion/baseimage
docker run -ti phusion/baseimage /bin/bash
</syntaxhighlight>
</syntaxhighlight>
* https://dockerfile.github.io/ which includes dockerfiles for different purposes. The ubuntu-desktop one also works well (client needs a vnc viewer in order to see the desktop).


=== Sharing data between containers ===
=== Set up a private Docker registry ===
[https://www.cloudsavvyit.com/15112/how-to-share-data-between-docker-containers/ How to Share Data Between Docker Containers]
* https://docs.docker.com/registry/ <syntaxhighlight lang='bash'>
 
docker run -d -p 5000:5000 --name registry registry:2
<syntaxhighlight lang='bash'>
docker pull ubuntu
docker run -it --name writer -v shared-data:/data alpine /bin/sh
docker image tag ubuntu localhost:5000/myfirstimage
# create a file inside it
docker push localhost:5000/myfirstimage
# echo 'my sample file' > /data/sample.txt
docker pull localhost:5000/myfirstimage
# exit
docker container stop registry && docker container rm -v registry
docker run -it --name reader -v shared-data:/app/data:ro ubuntu:17.04 /bin/bash
</syntaxhighlight>
# ls -l /app/data
* https://docs.docker.com/registry/deploying/
* [https://www.digitalocean.com/community/tutorials/how-to-set-up-a-private-docker-registry-on-ubuntu-14-04 Ubuntu 14.04] from digitalocean
* [https://www.howtoforge.com/tutorial/how-to-setup-private-docker-registry-on-ubuntu-1804-lts/ How to Setup Private Docker Registry on Ubuntu 18.04 LTS]
* [http://www.thegeekstuff.com/2017/01/secure-docker-registry/ How to Setup Secure Docker Registry on Linux using TLS SSL Certificate]
* List repositories in the local registry. [https://docs.docker.com/registry/spec/api/#listing-image-tags Docker Registry HTTP API V2] and [https://stackoverflow.com/a/14978657 HTTP POST and GET using cURL in Linux].
: <syntaxhighlight lang='bash'>
$ curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://localhost:5000/v2/_catalog
$ OR
$ curl -H "Accept: application/xml" -H "Content-Type: application/json" -X GET http://localhost:5000/v2/_catalog
</syntaxhighlight>
</syntaxhighlight>
* [https://www.howtogeek.com/devops/how-to-login-to-docker-hub-and-private-registries-with-the-docker-cli/ How to Login to Docker Hub and Private Registries With The Docker CLI]


=== Using host volumes ===
=== Github registry ===
Use volumes that mount a specific host folder
* [https://www.docker.com/blog/docker-support-for-the-new-github-container-registry/ Docker Support for the New GitHub Container Registry]
* It may be possible for the "docker volume" command to mount a local directory to a volume. See [https://docs.docker.com/engine/reference/commandline/volume_create/#examples examples] in the "docker volume create" documentation.
* [https://docs.github.com/en/packages/guides/migrating-to-github-container-registry-for-docker-images Migrating to GitHub Container Registry for Docker images]
* Specifying a directory name instead of giving a volume name in the "docker run" 's '''-v''' option
* [https://www.cloudsavvyit.com/6871/how-to-get-started-with-githubs-new-docker-container-registry/ How to Get Started with Github’s New Docker Container Registry]
* Since we are specifying a directory name instead of letting docker to create a new volume, "docker volume ls" will not getting a new volume
* [https://nikiforovall.github.io/docker/2020/09/19/publish-package-to-ghcr.html Publish images to GitHub Container Registry (ghcr)]
<syntaxhighlight lang='bash'>
docker run -it --name test -v $(pwd)/src:/app/src alpine /bin/sh


# Make a sample to demonstrate how that works
=== Google cloud registry ===
mkdir ~/my-web; cd ~/my-web
[https://seandavi.github.io/2019/02/using-google-cloud-registry-for-private-docker-images/ Using google cloud registry for private docker images]
echo "<h1>My website</h1>" > index.html


# Create 'Dockerfile'
== Dockerfile ==
echo -e 'FROM nginx:alpine
* [https://docs.docker.com/reference/builder/ Dockerfile Reference]
COPY . /usr/share/nginx/html' > Dockerfile
* [https://www.digitalocean.com/community/tutorials/docker-explained-using-dockerfiles-to-automate-building-of-images Using Dockerfiles to Automate Building of Images] from digitalocean.com.
* <strike><span style="color: red">Remember to put the Dockerfile in an empty directory</span></strike>.
* [https://medium.com/better-programming/what-goes-into-a-dockerfile-ff0ace591060 What goes into a Dockerfile]
* Keywords
** FROM. If we want to start from scratch, we can use ''FROM scratch''.
** RUN. The argument for RUN is any valid Linux command.
** [https://docs.docker.com/engine/reference/builder/#user USER]. This is useful if we want to create new files with a non-root owner privilege. For example, new files created under a binding directory with a non-root user ownership will belong to the current user in the host system. [https://github.com/jlintusaari/R-docker-report.git Here] is an example where we use Rmarkdown to create pdf output. The generated pdf file should not be own by root. [https://stackoverflow.com/a/27703359 How to add users to Docker container?] [https://biolitika.si/pin-r-package-versions-using-docker-and-renv.html Switch users].
** COPY & ADD.
*** "COPY . /app" will copy all files and folders from the current directory recursively to the /app folder. We can use "ADD" too but "ADD" will automatically unpack tarballs. See [https://stackoverflow.com/a/24958548 What is the difference between the `COPY` and `ADD` commands in a Dockerfile?]
*** "ADD sample.tar /app/bin" will unpack the ''sample.tar' file into the target folder
*** "ADD <nowiki>http://example.com/sample.txt</nowiki> /data/" will copy the remote file sample.txt into the target file
** WORKDIR. Define the working directory or context that is used when a container is run from the image.
** CMD & ENTRYPOINT. These two are actually definitions of what will happen when a container is started from the image.
*** Use CMD without ENTRYPOINT: "CMD command param1 param2". This form is called the '''shell''' form.
*** If we use ENTRYPOINT + CMD, ENTRYPOINT defines the command and CMD defines parameters. The example above will run ''ping 8.8.8.8 -c 3''. This form is called the '''exec''' form.
* [https://github.com/jamtur01/dockerbook-code The Docker Book]
* [https://github.com/rocker-org/rocker rocker (R and RStudio)]
* [https://github.com/Bioconductor/bioc_docker/tree/master/out Bioconductor]


docker image build -t my-website:1.0 .
=== Examples of Dockerfile ===
docker run -d -p 8080:80 --name my-site my-website:1.0
* [https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#minimize-the-number-of-layers Only the instructions RUN, COPY, ADD create layers.]
 
* A sample. Six layers (lines). The first line is the Base Layer.
# Open http://localhost:8080. It looks good
<pre>
# Now modify index.html and refresh the website. It does not refresh
FROM python:2.7
# Let's stop and rm the container and rebuild using a volume
RUN mkdir -p /app
docker rm -f my-site
WORKDIR /app
docker run -d -v $(pwd):/usr/share/nginx/html \
COPY ./requirements.txt /app/
  -p 8080:80 --name my-site my-website:1.0
RUN pip install -r requirements.txt
# Now any changes on index.html will refresh on the website
CMD ["python", "main.py"]
</syntaxhighlight>
</pre>
 
* Another example
=== Define volumes in images ===
A few samples of volume definition
<pre>
<pre>
VOLUME /app/data
FROM alpine:latest
VOLUME /app/data, /app/profiles, /app/config
ENTRYPOINT ["ping"]
VOLUME {"/app/data", "/app/profiles", "/app/config"]
CMD ["8.8.8.8", "-c", "3"]
</pre>
</pre>
The first line defines a single volume to be mounted at ''/app/data''.
* Another example from [https://github.com/rocker-org/rocker/blob/master/r-base/4.0.0/Dockerfile RStudio]
 
<pre>
We can use the ''docker image inspect'' command to get information about the volumes defined in the Dockerfile.
FROM debian:testing
<syntaxhighlight lang='bash'>
RUN useradd docker \
docker image pull mongo:3.7
&& mkdir /home/docker \
docker image inspect --format='{{json .ContainerConfig.Volumes}}' \
&& chown docker:docker /home/docker \
      mongo:3.7 | jq
&& addgroup docker staff
# {
</pre>
"/data/configdb": {},
We can test it by "docker build -t mydebian .  " and "docker run --rm -it --user docker -v /tmp:/home/docker mydebian". We can create a new file under /home/docker and the file will be accessible and belongs to the current host user once we quit the container. '''This actually is a huge security issue'''.
"/data/db": {}
# }


# now run an instance of MongoDB and inspect the volume information
The same technique does not work on alpine if I try to create a new file in the container.
docker run --name my-mongo -d mongo:3.7
<pre>
docker inspect --format '{{json .Mounts}}' my-mongo | jq
FROM alpine:latest
# [
# Create a group and user; not useful for creating files in host OS
# {
RUN addgroup -S appgroup && adduser -S appuser -G appgroup \
#    "Type": "volume",
          && chown appuser:appgroup /home/appuser
#    "Name": "535e0138b9a32e89f71380e9e73bb0de64ce0d1cad78fcda0ec1d49e11d76d7a",
</pre>
#    "Source": "/var/lib/docker/volumes/535e0138b9a32e89f71380e9e73bb0de64ce0d1.../_data",
"docker build -t myalpine .  " and "docker run --rm -it -v ~/Downloads/:/home/appuser:rw --user appuser myalpine". When I use the "id" command in the container, I see it returns 100 in alpine container and 1000 in debian container.  The id returns 1000 on my host (Ubuntu/Pop_OS). So the solution is '''docker run --rm -it -v ~/Downloads/:/home/appuser --user 1000:1000 myalpine'''. So the local user and the created user home directory in the container are not needed. See
#    "Destination": "/data/configdb",
<ul>
#    "Driver": "local",
<ul>
#    "Mode": "",
<li> [https://jtreminio.com/blog/running-docker-containers-as-current-host-user/ Running Docker Containers as Current Host User] (Useful !)</li>
#    "RW": true,
<li> [https://stackoverflow.com/a/45673309 How to give non-root user in Docker container access to a volume mounted on the host] </li>
#    "Propagation": ""
</ul></ul>
# },
 
# {
=== How to use Dockerfile ===
#    "Type": "volume",
https://docs.docker.com/engine/reference/commandline/build/
# SKIP
 
[https://stackoverflow.com/a/55034787 The . simply means "current working directory"].
<syntaxhighlight lang='bash'>
docker build -f Dockerfile -t arraytools/myimagename .
 
docker build -t [myname] .  
# Multiple tags
docker build -t arraytools/biospear:latest -t arraytools/biospear:3.6.0 .
</syntaxhighlight>
</syntaxhighlight>


=== Differences between VOLUME and '-v|--volume' ===
In the above example, we can create the image by
https://stackoverflow.com/a/25312719
<syntaxhighlight lang='bash'>
docker image build -t pinger .
</syntaxhighlight>
We can run a container from the pinger image
<syntaxhighlight lang='bash'>
docker container run --rm -it pinger
</syntaxhighlight>


=== Backup and restore container ===
=== Docker Build Args ===
* https://docs.docker.com/storage/volumes/#backup-restore-or-migrate-data-volumes
[https://www.howtogeek.com/devops/how-to-use-docker-build-args-to-configure-image-builds/ How to Use Docker Build Args to Configure Image Builds]
* [https://stackoverflow.com/a/28145912 Backup a running Docker container?]
* [https://www.maketecheasier.com/copy-move-docker-container-to-another-host/ How to Copy/Move a Docker Container to Another Host]


=== Container Memory Limits, Setting Available CPUs, Allocating memory and CPU ===
=== Clean up after failed builds ===
* [https://medium.com/@nitesh.turaga/how-i-use-bioconductor-with-docker-part-2-more-memory-faster-bioconductor-with-docker-fd7e69dce2bf How I use Bioconductor with Docker (part 2): More memory, faster Bioconductor with Docker]
[https://gist.github.com/kuznero/0c751283ea77177a1db9 Cleanup docker images and containers after failed builds]
: <syntaxhighlight lang='bash'>
docker run \
    -rm \ ## Automatically remove the container when it exits
    --memory=6g \ ## memory limit
    --cpus=1.5 \ ## number of CPUs
    -v /shared/data-store:/home/rstudio/data \
    -v /shared/library-store:/usr/local/lib/R/host-site-library \
    -e PASSWORD=bioc \
    -p 8787:8787 \
        bioconductor/bioconductor_full:devel
</syntaxhighlight>
* [https://docs.docker.com/docker-for-mac/ Get started with Docker Desktop for Mac], [https://docs.docker.com/docker-for-windows/ Windows]
* [https://docs.docker.com/config/containers/resource_constraints/ Limit a container's resources]
* [https://blog.docker.com/2018/12/top-5-post-docker-container-java/ TOP 5 BLOG OF 2018: IMPROVED DOCKER CONTAINER INTEGRATION WITH JAVA 10]
* [https://www.jottr.org/2022/04/22/parallelly-1.31.1/ parallelly 1.31.1: Better at Inferring Number of CPU Cores with Cgroups and Linux Containers]
* [https://www.thorsten-hans.com/limit-memory-for-docker-containers Docker Container Memory Limits Explained]
 
== Work with container images ==
* https://docs.docker.com/userguide/dockerimages/
 
=== List images by size or name ===
<pre>
<pre>
# by size
#!/bin/bash
docker images --format "{{.ID}}\t{{.Size}}\t{{.Repository}}" | sort -k 2 -h
docker rm $(docker ps -aq) \
 
  docker rmi $(docker images | grep "^<none>" | awk '{print $3}')
# by name
docker images --format "{{.ID}}\t{{.Size}}\t{{.Repository}}" | sort -k 3  
</pre>
</pre>


=== List specific columns ===
=== ENTRYPOINT and CMD ===
<pre>
* If your container acts like a command-line program, you can use '''ENTRYPOINT'''. If you are unsure, you can use '''CMD'''.
docker images --format 'table {{.Repository}}\t{{.Tag}}\t{{.Size}}'
* [https://blog.codeship.com/understanding-dockers-cmd-and-entrypoint-instructions/ Understanding Docker’s CMD and ENTRYPOINT Instructions]. It shows how to supply arguments to the command we like to execute in the container.
</pre>
* https://docs.docker.com/engine/reference/builder/#cmd
** [https://dille.name/blog/2019/12/05/creating-advanced-entrypoints-for-containers/ Creating Advanced Entrypoints for Containers]. In this case CMD provides extra parameters to ENTRYPOINT.
** The Dockerfile from [https://jlintusaari.github.io/2018/07/how-to-compile-rmarkdown-documents-using-docker/ How to compile R Markdown documents using Docker] uses both ENTRYPOINT and CMD where in this case CMD provides extra parameters to ENTRYPOINT.


=== Create an image interactively using '''commit''' - Example 1 ===
'''The advantage of using ENTRYPOINT + CMD''' (exec form) instead of using '''CMD''' alone (shell form) is we can override the ''CMD'' part that I have defined in the Dockerfile.
The example is from the book 'Learn Docker - Fundamentals of Docker 18.x'.
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker container run -it --name sample alpine /bin/sh
docker container run --rm -it pinger -w 5 127.0.0.1
# apk update && apk add iputils
# ping the loopback for 5 seconds
# ping 127.0.0.1
# exit
docker container ls -a | grep sample
docker container diff sample
</syntaxhighlight>
We can now use the ''docker container commit'' command to persist our modifications and create a new image from them
<syntaxhighlight lang='bash'>
docker container commit sample my-alpine
docker images ls
</syntaxhighlight>
</syntaxhighlight>


If we want to see how our custom image has been built, we can use the ''history'' command as follows:
If we want to overwrite what's defined in the ''ENTRYPOINT'' in the Dockerfile, we need to use the ''--entrypoint'' parameter.
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker image history my-alpine
docker container run --rm -it --entrypoint /bin/sh pinger
# IMAGE              CREATED              CREATED BY                                      SIZE    COMMENT
# we'll be inside the container. Type exit to leave the container
# 0f105057899b        About a minute ago  /bin/sh                                        1.55MB             
# 196d12cf6ab1        4 weeks ago          /bin/sh -c #(nop)  CMD ["/bin/sh"]              0B                 
# <missing>          4 weeks ago          /bin/sh -c #(nop) ADD file:25c10b1d1b41d46a1…  4.41MB
</syntaxhighlight>
</syntaxhighlight>
The first layer in the preceding list is the one we just created by adding the iputils package.


=== Create an image interactively using '''commit''' - Example 2 ===
When we use the '''shell''' form, the '''ENTRYPOINT''' is have the default value of ''/bin/sh -c'' and whatever is the value of ''CMD'' will be passed as a string to the shell command.
* [https://www.cloudsavvyit.com/15489/how-to-create-a-docker-image-from-a-running-container/ How to Create a Docker Image From a Running Container]. Commit messages are displayed when you use the '''docker history''' command to view the layers in an image.  
 
* [http://www.techrepublic.com/article/how-to-commit-changes-to-a-docker-image/ How to commit changes to a docker image]
=== Temporary failure resolving 'deb.debian.org' when running "docker build" ===
Add "--net=host" to the docker build command. See [https://stackoverflow.com/questions/24991136/docker-build-could-not-resolve-archive-ubuntu-com-apt-get-fails-to-install-a Docker build “Could not resolve 'archive.ubuntu.com'” apt-get fails to install anything]
 
=== Best practices for writing Dockerfiles ===
* https://docs.docker.com/develop/develop-images/dockerfile_best-practices/
* [https://blog.docker.com/2019/07/intro-guide-to-dockerfile-best-practices/ Intro Guide to Dockerfile Best Practices]


<span style="color: red">Note that it is better/necessary to put the Dockerfile in an empty directory</span> to avoid the problem of taking a long time to build the image (''sending build context to Docker daemon ...GB '') since it will grab files from the current directory.
=== Use multi-stage builds ===
* https://docs.docker.com/develop/develop-images/multistage-build/
* [https://www.cloudsavvyit.com/9260/what-are-multi-stage-docker-builds/ What Are Multi-Stage Docker Builds?]


<syntaxhighlight lang='bash'>
With multi-stage builds, we have a single Dockerfile containing multiple FROM instructions. Each FROM instruction is a new '''build stage''' that can easily COPY artifacts from previous '''stages'''.
sudo docker search sinatra
sudo docker pull training/sinatra
sudo docker run -t -i training/sinatra /bin/bash
sudo docker commit -m="Added json gem" -a="Kate Smith" 0b2616b0e5a8 ouruser/sinatra:v2
sudo docker images


mkdir sinatra
[https://github.com/nigelpoulton/atsea-sample-shop-app An example] from the "Docker Deep Dive" book.
cd sinatra
touch Dockerfile
sudo docker build -t="ouruser/sinatra:v2" .
sudo docker push ouruser/sinatra
sudo docker rmi training/sinatra
</syntaxhighlight>


* I get an error when I try to launch sinatra on my 32-bit ubuntu (Docker can only be installed through apt-get on 32-bit)
=== tag after image was built ===
<pre>
<pre>
$ sudo docker run -t -i training/sinatra /bin/bash
$ docker tag <imageID> <newName>/<repoName>:<tagName>
2014/12/31 02:43:26 exec format error
</pre>
</pre>


=== How to copy Docker images from one host to another without using a repository ===
=== About storage drivers ===
https://stackoverflow.com/questions/23935141/how-to-copy-docker-images-from-one-host-to-another-without-using-a-repository
https://docs.docker.com/storage/storagedriver/#sharing-promotes-smaller-images
<syntaxhighlight lang='bash'>
docker save -o out.tar <image name>
# Or better to compress the file
docker save <docker image name> | gzip > out.tar.gz
</syntaxhighlight>
And restore
<syntaxhighlight lang='bash'>
docker load -i out.tar
# Or decompress the file
docker load < out.tar.gz
</syntaxhighlight>


=== Docker Image Manifest ===
=== Privileged versus Root user in Docker ===
[https://www.cloudsavvyit.com/12330/what-is-a-docker-image-manifest/ What Is a Docker Image Manifest?]
* [https://www.cloudsavvyit.com/5211/privileged-vs-root-in-docker-whats-the-difference/ Privileged versus Root in Docker: What’s the Difference?]
* [https://itnext.io/docker-and-kubernetes-root-vs-privileged-9d2a37453dec Docker and Kubernetes — root vs. privileged]


=== Resources allocated to a container using docker? ===
=== .dockerignore ===
https://stackoverflow.com/questions/16084741/how-do-i-set-resources-allocated-to-a-container-using-docker
[https://devopsheaven.com/docker/dockerignore/2018/04/25/using-dockerignore.html Using .dockerignore files to build better Docker images]


== hub.docker.com ==
=== Dockerfile in One Line ===
* Note that Dockerfile is optional on https://registry.hub.docker.com.
<pre>
* For free account, we can have only [https://docs.docker.com/docker-hub/repos/ 1 free private repository]. If we want to create a new repository online, we can
FROM ubuntu
: <syntaxhighlight lang='bash'>
</pre>
docker tag local-image:tagname new-repo:tagname
Using This simple Dockerfile and the docker command '''sudo docker build -t scooby_snacks .''' will result in
docker login
<pre>
docker push new-repo:tagname
$ sudo docker images
</syntaxhighlight>
REPOSITORY          TAG                IMAGE ID            CREATED            VIRTUAL SIZE
* [https://stackoverflow.com/a/28349540 How to push a docker image to a private repository]
ubuntu              15.04              2427658c75a1        42 hours ago        117.5 MB
* [https://registry.hub.docker.com/repos/rocker/ rocker]. The Dockerfile is included there. Question: how to automatically build the image rather than uploading pre-built image binaries to Docker Hub?
ubuntu              vivid              2427658c75a1        42 hours ago        117.5 MB
* Search all repositories related to [https://registry.hub.docker.com/search?q=r&searchfield= R]
ubuntu              vivid-20150218      2427658c75a1        42 hours ago        117.5 MB
* [http://phusion.github.io/baseimage-docker/ baseimage-docker]. I can use ping command without special argument when I start phusion/baseimage.
ubuntu              utopic-20150211    78949b1e1cfd        42 hours ago        194.4 MB
: <syntaxhighlight lang='bash'>
ubuntu              utopic              78949b1e1cfd        42 hours ago        194.4 MB
docker pull phusion/baseimage
ubuntu              14.10              78949b1e1cfd        42 hours ago        194.4 MB
docker run -ti phusion/baseimage /bin/bash
ubuntu              14.04              2d24f826cb16        42 hours ago        188.3 MB
</syntaxhighlight>
ubuntu              14.04.2            2d24f826cb16        42 hours ago        188.3 MB
* https://dockerfile.github.io/ which includes dockerfiles for different purposes. The ubuntu-desktop one also works well (client needs a vnc viewer in order to see the desktop).
ubuntu              trusty              2d24f826cb16        42 hours ago        188.3 MB
 
ubuntu              trusty-20150218.1  2d24f826cb16        42 hours ago        188.3 MB
=== Set up a private Docker registry ===
ubuntu             latest              2d24f826cb16        42 hours ago        188.3 MB
* https://docs.docker.com/registry/ <syntaxhighlight lang='bash'>
scooby_snacks      latest              2d24f826cb16        42 hours ago        188.3 MB
docker run -d -p 5000:5000 --name registry registry:2
ubuntu             precise            1f80e9ca2ac3        42 hours ago        131.5 MB
docker pull ubuntu
ubuntu             precise-20150212    1f80e9ca2ac3        42 hours ago        131.5 MB
docker image tag ubuntu localhost:5000/myfirstimage
ubuntu              12.04.5            1f80e9ca2ac3        42 hours ago        131.5 MB
docker push localhost:5000/myfirstimage
ubuntu              12.04              1f80e9ca2ac3        42 hours ago        131.5 MB
docker pull localhost:5000/myfirstimage
ubuntu             14.04.1            5ba9dab47459        3 weeks ago        188.3 MB
docker container stop registry && docker container rm -v registry
ubuntu              12.10              c5881f11ded9        8 months ago        172.2 MB
</syntaxhighlight>
ubuntu             quantal            c5881f11ded9        8 months ago        172.2 MB
* https://docs.docker.com/registry/deploying/
ubuntu              13.04              463ff6be4238        8 months ago        169.4 MB
* [https://www.digitalocean.com/community/tutorials/how-to-set-up-a-private-docker-registry-on-ubuntu-14-04 Ubuntu 14.04] from digitalocean
ubuntu              raring              463ff6be4238        8 months ago        169.4 MB
* [https://www.howtoforge.com/tutorial/how-to-setup-private-docker-registry-on-ubuntu-1804-lts/ How to Setup Private Docker Registry on Ubuntu 18.04 LTS]
ubuntu              13.10              195eb90b5349        8 months ago        184.7 MB
* [http://www.thegeekstuff.com/2017/01/secure-docker-registry/ How to Setup Secure Docker Registry on Linux using TLS SSL Certificate]
ubuntu              saucy              195eb90b5349        8 months ago        184.7 MB
* List repositories in the local registry. [https://docs.docker.com/registry/spec/api/#listing-image-tags Docker Registry HTTP API V2] and [https://stackoverflow.com/a/14978657 HTTP POST and GET using cURL in Linux].
ubuntu              10.04              3db9c44f4520        10 months ago      183 MB
: <syntaxhighlight lang='bash'>
ubuntu              lucid              3db9c44f4520        10 months ago      183 MB
$ curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://localhost:5000/v2/_catalog
</pre>
$ OR
$ curl -H "Accept: application/xml" -H "Content-Type: application/json" -X GET http://localhost:5000/v2/_catalog
</syntaxhighlight>


=== Github registry ===
== List all tags of an image ==
* [https://www.docker.com/blog/docker-support-for-the-new-github-container-registry/ Docker Support for the New GitHub Container Registry]
[https://stackoverflow.com/a/39454426 How can I list all tags for a Docker image on a remote registry?]
* [https://docs.github.com/en/packages/guides/migrating-to-github-container-registry-for-docker-images Migrating to GitHub Container Registry for Docker images]
* [https://www.cloudsavvyit.com/6871/how-to-get-started-with-githubs-new-docker-container-registry/ How to Get Started with Github’s New Docker Container Registry]
* [https://nikiforovall.github.io/docker/2020/09/19/publish-package-to-ghcr.html Publish images to GitHub Container Registry (ghcr)]


=== Google cloud registry ===
=== Tag the image with the git commit ID ===
[https://seandavi.github.io/2019/02/using-google-cloud-registry-for-private-docker-images/ Using google cloud registry for private docker images]
<pre>
$ docker build -t REPOS/IMAGE:$(git rev-parse --verify HEAD)
</pre>


== Dockerfile ==
== Run a shell script on host ==
* [https://docs.docker.com/reference/builder/ Dockerfile Reference]
* https://docs.docker.com/engine/reference/commandline/run/
* [https://www.digitalocean.com/community/tutorials/docker-explained-using-dockerfiles-to-automate-building-of-images Using Dockerfiles to Automate Building of Images] from digitalocean.com.
* [https://serverfault.com/questions/806812/docker-run-bash-script-then-remove-container This post] and [https://stackoverflow.com/questions/32163955/how-to-run-shell-script-on-host-from-docker-container this one]
* <strike><span style="color: red">Remember to put the Dockerfile in an empty directory</span></strike>.
<pre style="white-space: pre-wrap; /* CSS 3 */ white-space: -moz-pre-wrap; /* Mozilla, since 1999 */ white-space: -pre-wrap; /* Opera 4-6 */ white-space: -o-pre-wrap; /* Opera 7 */ word-wrap: break-word; /* IE 5.5+ */ " >
* [https://medium.com/better-programming/what-goes-into-a-dockerfile-ff0ace591060 What goes into a Dockerfile]
$ docker run -v /path/to/sample_script.sh:/sample_script.sh \
* Keywords
  --rm ubuntu bash sample_script.sh
** FROM. If we want to start from scratch, we can use ''FROM scratch''.
** RUN. The argument for RUN is any valid Linux command.
** [https://docs.docker.com/engine/reference/builder/#user USER]. This is useful if we want to create new files with a non-root owner privilege. For example, new files created under a binding directory with a non-root user ownership will belong to the current user in the host system. [https://github.com/jlintusaari/R-docker-report.git Here] is an example where we use Rmarkdown to create pdf output. The generated pdf file should not be own by root. [https://stackoverflow.com/a/27703359 How to add users to Docker container?] [https://biolitika.si/pin-r-package-versions-using-docker-and-renv.html Switch users].
** COPY & ADD.
*** "COPY . /app" will copy all files and folders from the current directory recursively to the /app folder. We can use "ADD" too but "ADD" will automatically unpack tarballs. See [https://stackoverflow.com/a/24958548 What is the difference between the `COPY` and `ADD` commands in a Dockerfile?]
*** "ADD sample.tar /app/bin" will unpack the ''sample.tar' file into the target folder
*** "ADD <nowiki>http://example.com/sample.txt</nowiki> /data/" will copy the remote file sample.txt into the target file
** WORKDIR. Define the working directory or context that is used when a container is run from the image.
** CMD & ENTRYPOINT. These two are actually definitions of what will happen when a container is started from the image.
*** Use CMD without ENTRYPOINT: "CMD command param1 param2". This form is called the '''shell''' form.
*** If we use ENTRYPOINT + CMD, ENTRYPOINT defines the command and CMD defines parameters. The example above will run ''ping 8.8.8.8 -c 3''. This form is called the '''exec''' form.
* [https://github.com/jamtur01/dockerbook-code The Docker Book]
* [https://github.com/rocker-org/rocker rocker (R and RStudio)]
* [https://github.com/Bioconductor/bioc_docker/tree/master/out Bioconductor]


=== Examples of Dockerfile ===
# GATK container example
* [https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#minimize-the-number-of-layers Only the instructions RUN, COPY, ADD create layers.]
# First we log in interactive and see where is the default location (/usr in this case)
* A sample. Six layers (lines). The first line is the Base Layer.
$ docker run --rm -i -t broadinstitute/gatk3:3.8-0 bash
<pre>
$ cat > tmp.sh << EOF
FROM python:2.7
> pwd
RUN mkdir -p /app
> ls
WORKDIR /app
> java -jar GenomeAnalysisTK.jar --version
COPY ./requirements.txt /app/
> EOF
RUN pip install -r requirements.txt
$ docker run --rm -v $(pwd):/usr/my broadinstitute/gatk3:3.8-0 bash my/tmp.sh
CMD ["python", "main.py"]
# ALTERNATIVELY, WE CAN PUT OUR SCRIPT IN THE TOP DIRECTORY (Hopefully the name is not duplicated)
$ docker run --rm -v $(pwd)/tmp.sh:/tmp.sh broadinstitute/gatk3:3.8-0 bash /tmp.sh
</pre>
</pre>
* Another example
* https://askubuntu.com/questions/890533/how-can-i-run-docker-commands-after-docker-run-from-a-script (need to leave a container open)
<pre>
<pre>
FROM alpine:latest
docker run -d -v$(pwd):/my SOMEIMAGE bash
ENTRYPOINT ["ping"]
docker exec -d Test bash /my/script.sh
CMD ["8.8.8.8", "-c", "3"]
</pre>
</pre>
* Another example from [https://github.com/rocker-org/rocker/blob/master/r-base/4.0.0/Dockerfile RStudio]
* Create a Dockerfile https://forums.docker.com/t/how-to-run-bash-command-after-startup/21631/2
<pre>
 
FROM debian:testing
== Link containers together ==
RUN useradd docker \
* https://docs.docker.com/userguide/dockerlinks/
&& mkdir /home/docker \
* [https://hub.docker.com/r/simplyintricate/mediawiki/ Mediawiki example]
&& chown docker:docker /home/docker \
&& addgroup docker staff
</pre>
We can test it by "docker build -t mydebian .  " and "docker run --rm -it --user docker -v /tmp:/home/docker mydebian". We can create a new file under /home/docker and the file will be accessible and belongs to the current host user once we quit the container. '''This actually is a huge security issue'''.


The same technique does not work on alpine if I try to create a new file in the container.
== Manage data in containers ==
<pre>
* https://docs.docker.com/storage/volumes/
FROM alpine:latest
* https://codereviewvideos.com/course/docker-tutorial-for-beginners/video/part-2-docker-volumes-volumes
# Create a group and user; not useful for creating files in host OS
RUN addgroup -S appgroup && adduser -S appuser -G appgroup \
          && chown appuser:appgroup /home/appuser
</pre>
"docker build -t myalpine . " and "docker run --rm -it -v ~/Downloads/:/home/appuser:rw --user appuser myalpine". When I use the "id" command in the container, I see it returns 100 in alpine container and 1000 in debian container.  The id returns 1000 on my host (Ubuntu/Pop_OS). So the solution is '''docker run --rm -it -v ~/Downloads/:/home/appuser --user 1000:1000 myalpine'''. So the local user and the created user home directory in the container are not needed. See
<ul>
<ul>
<li> [https://jtreminio.com/blog/running-docker-containers-as-current-host-user/ Running Docker Containers as Current Host User] (Useful !)</li>
<li> [https://stackoverflow.com/a/45673309 How to give non-root user in Docker container access to a volume mounted on the host] </li>
</ul></ul>


=== How to use Dockerfile ===
== Assign a static IP to a container ==
https://docs.docker.com/engine/reference/commandline/build/
* [https://www.cloudsavvyit.com/14508/how-to-assign-a-static-ip-to-a-docker-container/ How to Assign a Static IP to a Docker Container]
 
* https://stackoverflow.com/questions/27937185/assign-static-ip-to-docker-container <syntaxhighlight lang='bash'>
[https://stackoverflow.com/a/55034787 The . simply means "current working directory"].
# Step 1. create you own docker network (mynet123)
<syntaxhighlight lang='bash'>
docker network create --subnet=172.18.0.0/16 mynet123
docker build -f Dockerfile -t arraytools/myimagename .
# Step 2. simply run the image (I'll take ubuntu as example)
docker run --rm --net mynet123 --ip 172.18.0.22 -it ubuntu bash
# Check in the container shell
# Note that the container CAN access internet
apt install net-tools; ifconfig
exit
</syntaxhighlight>
* https://docs.docker.com/engine/reference/commandline/network_create/#bridge-driver-options
* [https://stackoverflow.com/questions/25529386/how-can-i-set-a-static-ip-address-in-a-docker-container Try using the --net=host option] (no a new IP was allocated; not a good solution)
 
== Running Multiple Docker Services on the Same Server ==
[https://www.howtogeek.com/devops/how-to-run-multiple-docker-containers-on-different-ip-addresses/ How to Run Multiple Docker Containers on Different IP Addresses]


docker build -t [myname] .
== Firewall ==
# Multiple tags
[https://community.rstudio.com/t/rstudio-server-not-loading-taking-too-long-to-respond-in-browser/20786 Rstudio server not loading, taking too long to respond in browser]. On Ubuntu run ''sudo ufw allow PORTNUMBER''.
docker build -t arraytools/biospear:latest -t arraytools/biospear:3.6.0 .
 
</syntaxhighlight>
== Docker DNS/internet problem ==
I got an error on resolving the debian server when I was creating an image from a Dockerfile that needs to run ''apt update'' and ''apt install'' commands. See [[#RStudio_in_Docker_.E2.80.93_now_share_your_R_code_effortlessly.21|RStudio in Docker – now share your R code effortlessly!]]. The problem happened on my Linux Mint Desktop but not on a VirtualBox VM (Ubuntu 18.04).


In the above example, we can create the image by
[https://development.robinwinslow.uk/2016/06/23/fix-docker-networking-dns/ Fix Docker's networking DNS config]
<syntaxhighlight lang='bash'>
docker image build -t pinger .
</syntaxhighlight>
We can run a container from the pinger image
<syntaxhighlight lang='bash'>
docker container run --rm -it pinger
</syntaxhighlight>


=== Clean up after failed builds ===
A temporary solution is to add the '''--dns''' option to ''docker run'' command. This works well when I use the IP from any one of my 2 DNS servers. It does not work however if I use the IP from google DNS or OpenDNS.
[https://gist.github.com/kuznero/0c751283ea77177a1db9 Cleanup docker images and containers after failed builds]
<pre>
#!/bin/bash
docker rm $(docker ps -aq) \
  docker rmi $(docker images | grep "^<none>" | awk '{print $3}')
</pre>


=== ENTRYPOINT and CMD ===
A permanent solution is to create a new file '''/etc/docker/daemon.json''' and include the working DNS server IPs (these are obtained through the '''nmcli''' command or the NetworkManager GUI; see [[Linux#Query_DNS_server|Query DNS server]]).
* If your container acts like a command-line program, you can use '''ENTRYPOINT'''. If you are unsure, you can use '''CMD'''.
<pre>
* [https://blog.codeship.com/understanding-dockers-cmd-and-entrypoint-instructions/ Understanding Docker’s CMD and ENTRYPOINT Instructions]. It shows how to supply arguments to the command we like to execute in the container.
{
* https://docs.docker.com/engine/reference/builder/#cmd
    "dns": ["XXX.XX.XX.XX", "YYY.YY.YY.YY"]
** [https://dille.name/blog/2019/12/05/creating-advanced-entrypoints-for-containers/ Creating Advanced Entrypoints for Containers]. In this case CMD provides extra parameters to ENTRYPOINT.
}
** The Dockerfile from [https://jlintusaari.github.io/2018/07/how-to-compile-rmarkdown-documents-using-docker/ How to compile R Markdown documents using Docker] uses both ENTRYPOINT and CMD where in this case CMD provides extra parameters to ENTRYPOINT.
</pre>
Then restart the docker service: '''sudo service docker restart'''


'''The advantage of using ENTRYPOINT + CMD''' (exec form) instead of using '''CMD''' alone (shell form) is we can override the ''CMD'' part that I have defined in the Dockerfile.
A quick test on the DNS problem is  
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker container run --rm -it pinger -w 5 127.0.0.1
docker run --rm busybox nslookup google.com
# ping the loopback for 5 seconds
</syntaxhighlight>
</syntaxhighlight>


If we want to overwrite what's defined in the ''ENTRYPOINT'' in the Dockerfile, we need to use the ''--entrypoint'' parameter.
== Working with Docker hub ==
<syntaxhighlight lang='bash'>
https://docs.docker.com/userguide/dockerrepos/
docker container run --rm -it --entrypoint /bin/sh pinger
# we'll be inside the container. Type exit to leave the container
</syntaxhighlight>


When we use the '''shell''' form, the '''ENTRYPOINT''' is have the default value of ''/bin/sh -c'' and whatever is the value of ''CMD'' will be passed as a string to the shell command.
=== Github Actions ===
* [https://docs.github.com/en/actions/language-and-framework-guides/github-actions-for-docker GitHub Actions for Docker]
* [https://docs.github.com/en/actions/language-and-framework-guides/publishing-docker-images Publishing Docker images]
* See my [[Github#Github_Actions_.28GHA.29|Github]] page.


=== Temporary failure resolving 'deb.debian.org' when running "docker build" ===
== Enabling HTTPS/Let's encrypt ==
Add "--net=host" to the docker build command. See [https://stackoverflow.com/questions/24991136/docker-build-could-not-resolve-archive-ubuntu-com-apt-get-fails-to-install-a Docker build “Could not resolve 'archive.ubuntu.com'” apt-get fails to install anything]
* [https://caddyserver.com/ Caddy]
* https://hub.docker.com/r/jrcs/letsencrypt-nginx-proxy-companion
* [https://medium.com/bros/enabling-https-with-lets-encrypt-over-docker-9cad06bdb82b Enabling HTTPS with Let's Encrypt on Docker]
* [https://www.humankode.com/ssl/how-to-set-up-free-ssl-certificates-from-lets-encrypt-using-docker-and-nginx How to Set Up Free SSL Certificates from Let's Encrypt using Docker and Nginx] and the [https://github.com/thecarlo/letsencrypt-docker-nginx source code].
* [http://www.56n.dk/setup-encrypted-rstudio-and-shiny-dashboard-solution-in-3-minutes/ Setup encrypted Rstudio and Shiny dashboard solution in 3 minutes] (2017). Not working now. ERROR: manifest for mikkelkrogsholm/rstudio:latest not found. After changing to use rocker/rstudio & rocker/shiny images, a new error came out <syntaxhighlight lang='bash'>
ERROR: for nginx  Cannot start service nginx: b'driver failed programming external connectivity on endpoint
nginx (879b01885acd6a0778d9403f4220851e83bd2ff8de643ce91c21cecd25419f83): Error starting userland proxy:
listen tcp 0.0.0.0:443: bind: address already in use'
ERROR: Encountered errors while bringing up the project.
</syntaxhighlight>
* [https://medium.com/bros/enabling-https-with-lets-encrypt-over-docker-9cad06bdb82b Enabling HTTPS with Let's Encrypt on Docker] using Nginx.


=== Best practices for writing Dockerfiles ===
== Enabling HTTPS by self-sign certificates ==
* https://docs.docker.com/develop/develop-images/dockerfile_best-practices/
* [https://www.johnmackenzie.co.uk/post/creating-self-signed-ssl-certificates-for-docker-and-nginx/ Creating Self-Signed SSL Certificates For Docker and Nginx]
* [https://blog.docker.com/2019/07/intro-guide-to-dockerfile-best-practices/ Intro Guide to Dockerfile Best Practices]
* [https://medium.com/@oliver.zampieri/self-signed-ssl-reverse-proxy-with-docker-dbfc78c05b41 Self-signed SSL Reverse proxy with Docker]
* [https://codefresh.io/docker-tutorial/using-docker-generate-ssl-certificates/ Using Docker to Generate SSL Certificates]
* [https://medium.com/@mannycodes/configure-self-signed-ssl-for-nginx-docker-from-a-scratch-7c2bcd5478c6 Configure Self-Signed SSL For Nginx Docker From A Scratch]
* [https://smithtalkstech.com/2018/04/25/creating-a-self-signed-ssl-certificate-for-local-docker-development/ Creating a self-signed SSL certificate for local Docker development]


=== Use multi-stage builds ===
== traefik: The Cloud Native Application Proxy ==
* https://docs.docker.com/develop/develop-images/multistage-build/
* https://traefik.io/traefik/
* [https://www.cloudsavvyit.com/9260/what-are-multi-stage-docker-builds/ What Are Multi-Stage Docker Builds?]
* [https://www.digitalocean.com/community/tutorials/how-to-use-traefik-as-a-reverse-proxy-for-docker-containers-on-ubuntu-18-04 How To Use Traefik as a Reverse Proxy for Docker Containers on Ubuntu 18.04]
 
* [https://www.howtoforge.com/how-to-install-and-use-traefik-as-a-reverse-proxy-with-docker-on-centos-8/ How to Install and Use Traefik as a Reverse Proxy with Docker on CentOS 8]
With multi-stage builds, we have a single Dockerfile containing multiple FROM instructions. Each FROM instruction is a new '''build stage''' that can easily COPY artifacts from previous '''stages'''.
* [https://www.digitalocean.com/community/tutorials/how-to-use-traefik-v2-as-a-reverse-proxy-for-docker-containers-on-ubuntu-20-04 How To Use Traefik v2 as a Reverse Proxy for Docker Containers on Ubuntu 20.04]
 
* [https://medium.com/accesto/docker-reverse-proxy-using-traefik-2657c0086a3d Docker reverse proxy using Traefik]
[https://github.com/nigelpoulton/atsea-sample-shop-app An example] from the "Docker Deep Dive" book.
* [https://blog.eleven-labs.com/en/using-traefik-as-a-reverse-proxy/ USING TRAEFIK AS A REVERSE PROXY]
* [https://youtu.be/N5EmluXSbEg How to Install Traefik 2 on OMV and Docker] DB Tech 2020. Cloudflare, Portainer. Airsonic.
* [https://youtu.be/liV3c9m_OX8 Put Wildcard Certificates and SSL on EVERYTHING - Traefik Tutorial] Apr 2021
* Raspberry Pi
** [https://www.alexhyett.com/traefik-vs-nginx-docker-raspberry-pi Traefik vs Nginx for Reverse Proxy with Docker on a Raspberry Pi]
** [https://codecaptured.com/blog/self-hosting-pi-hole-with-docker-and-traefik/ Self-Hosting Pi-hole with Docker and Traefik]
** [https://blog.pankajgarg.com/helloaspnetcoreonpi/ Running ASP.NET core web application on Raspberry Pi]
* [https://youtu.be/liV3c9m_OX8 Put Wildcard Certificates and SSL on EVERYTHING - Traefik Tutorial] (video)


=== tag after image was built ===
== Nginx proxy manager ==
<pre>
* https://nginxproxymanager.com/
$ docker tag <imageID> <newName>/<repoName>:<tagName>
* [https://www.the-digital-life.com/nginx-proxy-manager/ NGINX Proxy Manager – How-To Installation and Configuration]
* [https://youtu.be/CSbgLBcIuwE Access your internal websites! Nginx Reverse Proxy in Home Assistant]
* [https://www.howtoforge.com/how-to-install-and-use-nginx-proxy-manager/ How to Install and Use Nginx Proxy Manager with Docker] 2022
* [https://www.the-digital-life.com/nginx-proxy-manager/ NGINX Proxy Manager – How-To Installation and Configuration] the-digital-life
* https://hub.docker.com/r/jlesage/nginx-proxy-manager, [https://github.com/jlesage/docker-nginx-proxy-manager Github]
* [https://dev.to/domysee/setting-up-a-reverse-proxy-with-nginx-and-docker-compose-29jg Setting up a Reverse-Proxy with Nginx and docker-compose]
* [https://linoxide.com/containers/setup-nginx-reverse-proxy-docker/ How to Setup NGINX as Reverse Proxy Using Docker]. It works.
** Download the code from https://github.com/a-magdy/nginx-reverse-proxy-docker.
** On the step of modifying /etc/hosts, change the IP address from 172.31.30.78 to 127.0.0.1 for site1.test and site2.test. Or I can use '''docker inspect XXXX | grep IPAddress''' to find out the IP for site1_default and site2_default (these two names are defined in <docker-compose.yml>).
** Before creating proxy container, though two web services are up and running inside container, we still cannot test site1.test and site2.test.
** docker-compose build shows successful build. But where is the image?
** ''curl site1.test'' and ''curl site2.test'' work fine.
** We can also use a browser to check these two URLs. For https it still works though FF gives warnings for self signed certificates.
** '''nmap localhost''' will show ports 80 & 443 are open.
* [https://www.freecodecamp.org/news/docker-nginx-letsencrypt-easy-secure-reverse-proxy-40165ba3aee2/ How to set up an easy and secure reverse proxy with Docker, Nginx]
* [http://littlebigextra.com/install-nginx-reverse-proxy-server-docker/ How to install Nginx as a reverse proxy server with Docker]. Note that http://microservice1:8080;  needs to be changed to reflect the true IP whether it is from a docker container or not. Also it does not work when I modify the --link option to use site1_app_1 and site2_app_1.
{{Pre}}
docker: Error response from daemon: Cannot link to /site1_app_1, as it does not belong to the default network.
</pre>
</pre>
* [https://phoenixnap.com/kb/docker-nginx-reverse-proxy How to Deploy NGINX Reverse Proxy on Docker] (multiple web services)
* [https://www.howtoforge.com/how-to-install-and-use-portainer-for-docker-management-with-nginx-proxy-manager/ How to Install and Use Portainer for Docker management with Nginx Proxy Manager]


=== About storage drivers ===
== Running multiple web applications on a Docker host ==
https://docs.docker.com/storage/storagedriver/#sharing-promotes-smaller-images
* https://medium.com/@jmarhee/running-multiple-web-applications-on-a-docker-host-with-apache-85f673f02803. Tips: Enable proxy module in Apache. In the ''VirtualHost'' file, specify '''ProxyPass''' with a port number. No need to specify the DocumentRoot.
* https://medium.com/@francoisromain/host-multiple-websites-with-https-inside-docker-containers-on-a-single-server-18467484ab95. Nginx reverse-proxy is used.
* https://blog.florianlopes.io/host-multiple-websites-on-single-host-docker/. [https://github.com/jwilder/nginx-proxy jwilder/nginx-proxy] is used. No need (and should not to avoid a conflict of port 80) to install Nginx <syntaxhighlight lang='bash'>
docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock jwilder/nginx-proxy
 
sudo nano /etc/hosts # add blog.domain.com and jenkins.domain.com for our testing purpose


=== Privileged versus Root user in Docker ===
docker run -d --expose 80 -e VIRTUAL_HOST=blog.domain.com wordpress
* [https://www.cloudsavvyit.com/5211/privileged-vs-root-in-docker-whats-the-difference/ Privileged versus Root in Docker: What’s the Difference?]
docker run -d --name jenkinsci --expose 8080 -e VIRTUAL_HOST=jenkins.domain.com -e VIRTUAL_PORT=8080 jenkins
* [https://itnext.io/docker-and-kubernetes-root-vs-privileged-9d2a37453dec Docker and Kubernetes — root vs. privileged]
</syntaxhighlight>
** Use VIRTUAL_PORT if there are multiple ports associated with a container
** Use VIRTUAL_HOST if there are multiple domains associated with a container
** SSL and et al


=== .dockerignore ===
== Authentication: Authelia ==
[https://devopsheaven.com/docker/dockerignore/2018/04/25/using-dockerignore.html Using .dockerignore files to build better Docker images]
[https://www.youtube.com/watch?v=4UKOh3ssQSU Additional Self-Hosted Security with Authelia on NGINX Proxy Manager] (video)


=== Dockerfile in One Line ===
== GUI apps ==
<pre>
* [https://www.cloudsavvyit.com/10520/how-to-run-gui-applications-in-a-docker-container/ How to Run GUI Applications in a Docker Container]
FROM ubuntu
* https://github.com/mviereck/x11docker/ which was used by [https://github.com/ehough/docker-kodi Docker-kodi]
</pre>
* https://pelle.io/2014/07/11/delivering-gui-applications-with-docker/ Forward X11 approach
Using This simple Dockerfile and the docker command '''sudo docker build -t scooby_snacks .''' will result in
* https://linuxmeerkat.wordpress.com/2014/10/17/running-a-gui-application-in-a-docker-container/ Forward X11
<pre>
* http://fabiorehm.com/blog/2014/09/11/running-gui-apps-with-docker/ Share X11 socket
$ sudo docker images
* https://github.com/rogaha/docker-desktop  Xpra + Xephyr
REPOSITORY          TAG                IMAGE ID            CREATED            VIRTUAL SIZE
* https://github.com/fcwu/docker-ubuntu-vnc-desktop VNC approach
ubuntu              15.04              2427658c75a1        42 hours ago        117.5 MB
ubuntu              vivid              2427658c75a1        42 hours ago        117.5 MB
ubuntu              vivid-20150218      2427658c75a1        42 hours ago        117.5 MB
ubuntu              utopic-20150211    78949b1e1cfd        42 hours ago        194.4 MB
ubuntu              utopic              78949b1e1cfd        42 hours ago        194.4 MB
ubuntu              14.10               78949b1e1cfd        42 hours ago        194.4 MB
ubuntu              14.04              2d24f826cb16        42 hours ago        188.3 MB
ubuntu              14.04.2            2d24f826cb16        42 hours ago        188.3 MB
ubuntu              trusty              2d24f826cb16        42 hours ago        188.3 MB
ubuntu             trusty-20150218.1  2d24f826cb16        42 hours ago        188.3 MB
ubuntu              latest              2d24f826cb16        42 hours ago        188.3 MB
scooby_snacks      latest              2d24f826cb16        42 hours ago        188.3 MB
ubuntu              precise            1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              precise-20150212    1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              12.04.5            1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              12.04              1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              14.04.1            5ba9dab47459        3 weeks ago        188.3 MB
ubuntu              12.10              c5881f11ded9        8 months ago        172.2 MB
ubuntu              quantal            c5881f11ded9        8 months ago        172.2 MB
ubuntu              13.04              463ff6be4238        8 months ago        169.4 MB
ubuntu              raring              463ff6be4238        8 months ago        169.4 MB
ubuntu              13.10              195eb90b5349        8 months ago        184.7 MB
ubuntu              saucy              195eb90b5349        8 months ago        184.7 MB
ubuntu              10.04              3db9c44f4520        10 months ago      183 MB
ubuntu              lucid              3db9c44f4520        10 months ago      183 MB
</pre>


== List all tags of an image ==
=== Docker-OSX ===
[https://stackoverflow.com/a/39454426 How can I list all tags for a Docker image on a remote registry?]
https://github.com/sickcodes/Docker-OSX


=== Tag the image with the git commit ID ===
== Pruning unused resources ==
<pre>
* Prune containers
$ docker build -t REPOS/IMAGE:$(git rev-parse --verify HEAD)
<syntaxhighlight lang='bash'>
</pre>
docker container prune # remove all containers that are not in ''running'' status
                      # Docker will ask for confirmation before deleting the containers


== Run a shell script on host ==
docker container prune -f
* https://docs.docker.com/engine/reference/commandline/run/
docker container rm -f $(docker container ls -aq) # remove even the running containers
* [https://serverfault.com/questions/806812/docker-run-bash-script-then-remove-container This post] and [https://stackoverflow.com/questions/32163955/how-to-run-shell-script-on-host-from-docker-container this one]
</syntaxhighlight>
<pre style="white-space: pre-wrap; /* CSS 3 */ white-space: -moz-pre-wrap; /* Mozilla, since 1999 */ white-space: -pre-wrap; /* Opera 4-6 */ white-space: -o-pre-wrap; /* Opera 7 */ word-wrap: break-word; /* IE 5.5+ */ " >
* Prune images
$ docker run -v /path/to/sample_script.sh:/sample_script.sh \
<syntaxhighlight lang='bash'>
  --rm ubuntu bash sample_script.sh
docker images prune # unused image layers
</syntaxhighlight>
* Prune volumes
<syntaxhighlight lang='bash'>
docker volume prune # unused volumes by at least one container


# GATK container example
docker volume prune --filter 'label=demo'
# First we log in interactive and see where is the default location (/usr in this case)
docker volume prune --filter 'label=demo' --filter 'label=test'
$ docker run --rm -i -t broadinstitute/gatk3:3.8-0 bash
</syntaxhighlight>
$ cat > tmp.sh << EOF
* Prune networks
> pwd
<syntaxhighlight lang='bash'>
> ls
docker network prune
> java -jar GenomeAnalysisTK.jar --version
</syntaxhighlight>
> EOF
* Prune everything
$ docker run --rm -v $(pwd):/usr/my broadinstitute/gatk3:3.8-0 bash my/tmp.sh
<syntaxhighlight lang='bash'>
# ALTERNATIVELY, WE CAN PUT OUR SCRIPT IN THE TOP DIRECTORY (Hopefully the name is not duplicated)
docker system prune
$ docker run --rm -v $(pwd)/tmp.sh:/tmp.sh broadinstitute/gatk3:3.8-0 bash /tmp.sh
</syntaxhighlight>
</pre>
* https://askubuntu.com/questions/890533/how-can-i-run-docker-commands-after-docker-run-from-a-script (need to leave a container open)
<pre>
docker run -d -v$(pwd):/my SOMEIMAGE bash
docker exec -d Test bash /my/script.sh
</pre>
* Create a Dockerfile https://forums.docker.com/t/how-to-run-bash-command-after-startup/21631/2


== Link containers together ==
== Plugins ==
* https://docs.docker.com/userguide/dockerlinks/
[https://www.cloudsavvyit.com/15066/how-to-manage-docker-engine-plugins/ How to Manage Docker Engine Plugins]
* [https://hub.docker.com/r/simplyintricate/mediawiki/ Mediawiki example]


== Manage data in containers ==
== Misc ==
* https://docs.docker.com/storage/volumes/
=== LXC (raw Linux containers) ===
* https://codereviewvideos.com/course/docker-tutorial-for-beginners/video/part-2-docker-volumes-volumes
* https://help.ubuntu.com/lts/serverguide/lxc.html
* https://help.ubuntu.com/community/LXC
* https://askubuntu.com/questions/293275/what-is-lxc-and-how-to-get-started
* [https://www.cyberciti.biz/faq/how-to-install-lxd-container-hypervisor-on-ubuntu-16-04-lts-server/ Setup Linux Container with LXC on Ubuntu 16.04]
* [http://en.community.dell.com/techcenter/os-applications/w/wiki/6950.lxc-containers-in-ubuntu-server-14-04-lts LXC containers in Ubuntu Server 14.04 LTS]
* [https://blog.simos.info/trying-out-lxd-containers-on-our-ubuntu/ Trying out LXD containers on our Ubuntu]


== Assign a static IP to a container ==
==== LXC vs Docker ====
* [https://www.cloudsavvyit.com/14508/how-to-assign-a-static-ip-to-a-docker-container/ How to Assign a Static IP to a Docker Container]
* https://diveintodocker.com/blog/why-i-got-started-with-docker
* https://stackoverflow.com/questions/27937185/assign-static-ip-to-docker-container <syntaxhighlight lang='bash'>
* https://unix.stackexchange.com/questions/254956/what-is-the-difference-between-docker-lxd-and-lxc and https://i.stack.imgur.com/a5Neb.png
# Step 1. create you own docker network (mynet123)
docker network create --subnet=172.18.0.0/16 mynet123
# Step 2. simply run the image (I'll take ubuntu as example)
docker run --rm --net mynet123 --ip 172.18.0.22 -it ubuntu bash
# Check in the container shell
# Note that the container CAN access internet
apt install net-tools; ifconfig
exit
</syntaxhighlight>
* https://docs.docker.com/engine/reference/commandline/network_create/#bridge-driver-options
* [https://stackoverflow.com/questions/25529386/how-can-i-set-a-static-ip-address-in-a-docker-container Try using the --net=host option] (no a new IP was allocated; not a good solution)


== Firewall ==
=== Vagrant vs Docker ===
[https://community.rstudio.com/t/rstudio-server-not-loading-taking-too-long-to-respond-in-browser/20786 Rstudio server not loading, taking too long to respond in browser]. On Ubuntu run ''sudo ufw allow PORTNUMBER''.
* http://stackoverflow.com/questions/16647069/should-i-use-vagrant-or-docker-io-for-creating-an-isolated-environment
* https://deliciousbrains.com/vagrant-docker-wordpress-development/
** Vagrant is easier to understand and is easier to get up and running but can be very resource intensive (in terms of RAM and space).
** Docker’s architecture is harder to understand and can be harder to get up and running but is much faster, uses much less CPU and RAM and potentially uses much less space than Vagrant VM’s.
* https://youtu.be/9QGkJvbLpRA?t=3m22s
** Docker uses container technology while vagrant uses virtual machines.
** If security is a concern, use vagrant and virtual machine
** For speeding development and sharing, use Docker.
** Most teams use both to run a smooth operation


== Docker DNS/internet problem ==
=== Date/Time zone ===
I got an error on resolving the debian server when I was creating an image from a Dockerfile that needs to run ''apt update'' and ''apt install'' commands. See [[#RStudio_in_Docker_.E2.80.93_now_share_your_R_code_effortlessly.21|RStudio in Docker – now share your R code effortlessly!]]. The problem happened on my Linux Mint Desktop but not on a VirtualBox VM (Ubuntu 18.04).
* List of time zone. [https://docs.diladele.com/docker/timezones.html Setting Local Time in Docker]; e.g. "America/New_York" or "US/Eastern".
* https://stackoverflow.com/questions/22800624/will-docker-container-auto-sync-time-with-the-host-machine
<syntaxhighlight lang='bash'>
docker run --rm -t -i -v /etc/localtime:/etc/localtime:ro ubuntu date
</syntaxhighlight>
* https://serverfault.com/questions/683605/docker-container-time-timezone-will-not-reflect-changes
 
=== Access the internet from the container ===
Run the container with the '--net=host' option
<syntaxhighlight lang='bash'>
sudo docker run --net=host -it ubuntu /bin/bash
</syntaxhighlight>


[https://development.robinwinslow.uk/2016/06/23/fix-docker-networking-dns/ Fix Docker's networking DNS config]
=== How to transfer/copy an image to another host ===
[https://stackoverflow.com/a/23938978 How to copy Docker images from one host to another without using a repository]
<syntaxhighlight lang='bash'>
# Step 1: save the Docker image as a tar file:
docker save -o <path for generated tar file> <image name>


A temporary solution is to add the '''--dns''' option to ''docker run'' command. This works well when I use the IP from any one of my 2 DNS servers. It does not work however if I use the IP from google DNS or OpenDNS.
# Step 2: copy your image to a new system with regular file transfer tools such as cp or scp.  


A permanent solution is to create a new file '''/etc/docker/daemon.json''' and include the working DNS server IPs (these are obtained through the '''nmcli''' command or the NetworkManager GUI; see [[Linux#Query_DNS_server|Query DNS server]]).
# Step 3: After that you will have to load the image into Docker:
<pre>
docker load -i <path to image tar file>
{
</syntaxhighlight>
    "dns": ["XXX.XX.XX.XX", "YYY.YY.YY.YY"]
The tar file size is the same as what we get from 'docker image'. If we use the 'gzip' utility, it can reduce the file size (e.g 2.7GB to 1.1GB).
}
</pre>
Then restart the docker service: '''sudo service docker restart'''


A quick test on the DNS problem is
Or https://stackoverflow.com/a/39716019
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker run --rm busybox nslookup google.com
# Step 1:
docker save docker-image-name | gzip > my-image.tar.gz
# Step 3:
docker load < my-image.tar.gz
</syntaxhighlight>
</syntaxhighlight>


== Working with Docker hub ==
=== Where are Docker images stored on the host: /var/lib/docker ===
https://docs.docker.com/userguide/dockerrepos/
* http://blog.thoward37.me/articles/where-are-docker-images-stored/
* http://stackoverflow.com/questions/19234831/where-are-docker-images-stored-on-the-host-machine
* https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-storage-driver
* http://stackoverflow.com/questions/21016210/function-of-docker-directory-structure-in-var-lib-docker
* [https://foxutech.com/manage-docker-images-local-disk/ How to Manage Docker images on local disk]


=== Github Actions ===
The default is '''/var/lib/docker'''. The location can be changed by modifying the file '''/etc/default/docker'''. Three options if we are tight on the disk space.
* [https://docs.github.com/en/actions/language-and-framework-guides/github-actions-for-docker GitHub Actions for Docker]
* [https://docs.github.com/en/actions/language-and-framework-guides/publishing-docker-images Publishing Docker images]
* See my [[Github#Github_Actions_.28GHA.29|Github]] page.


== Enabling HTTPS/Let's encrypt ==
'''1. Create a softlinks''' for the Docker data directory (/var/lib/docker) and for /var/lib/docker/tmp as described at [https://docs.docker.com/engine/reference/commandline/dockerd/#miscellaneous-options miscellaneous-options]. See [https://stackoverflow.com/a/40919928 this]. See [https://stackoverflow.com/a/40192707 for how to stop docker daemon] on different OS.
* [https://caddyserver.com/ Caddy]
<syntaxhighlight lang='bash'>
* https://hub.docker.com/r/jrcs/letsencrypt-nginx-proxy-companion
sudo service docker stop  # or sudo systemctl stop docker
* [https://medium.com/bros/enabling-https-with-lets-encrypt-over-docker-9cad06bdb82b Enabling HTTPS with Let's Encrypt on Docker]
sudo mv /var/lib/docker /a/new/location
* [https://www.humankode.com/ssl/how-to-set-up-free-ssl-certificates-from-lets-encrypt-using-docker-and-nginx How to Set Up Free SSL Certificates from Let's Encrypt using Docker and Nginx] and the [https://github.com/thecarlo/letsencrypt-docker-nginx source code].
sudo ln -s /a/new/location /var/lib/docker # Create a symbolic link
* [http://www.56n.dk/setup-encrypted-rstudio-and-shiny-dashboard-solution-in-3-minutes/ Setup encrypted Rstudio and Shiny dashboard solution in 3 minutes] (2017). Not working now. ERROR: manifest for mikkelkrogsholm/rstudio:latest not found. After changing to use rocker/rstudio & rocker/shiny images, a new error came out <syntaxhighlight lang='bash'>
sudo service docker start  # or sudo systemctl start docker
ERROR: for nginx  Cannot start service nginx: b'driver failed programming external connectivity on endpoint
nginx (879b01885acd6a0778d9403f4220851e83bd2ff8de643ce91c21cecd25419f83): Error starting userland proxy:
listen tcp 0.0.0.0:443: bind: address already in use'
ERROR: Encountered errors while bringing up the project.
</syntaxhighlight>
</syntaxhighlight>
* [https://medium.com/bros/enabling-https-with-lets-encrypt-over-docker-9cad06bdb82b Enabling HTTPS with Let's Encrypt on Docker] using Nginx.


== Enabling HTTPS by self-sign certificates ==
'''2. Change the default location to another place'''. For example,
* [https://www.johnmackenzie.co.uk/post/creating-self-signed-ssl-certificates-for-docker-and-nginx/ Creating Self-Signed SSL Certificates For Docker and Nginx]
<syntaxhighlight lang='bash'>
* [https://medium.com/@oliver.zampieri/self-signed-ssl-reverse-proxy-with-docker-dbfc78c05b41 Self-signed SSL Reverse proxy with Docker]
sudo nano /etc/default/docker
* [https://codefresh.io/docker-tutorial/using-docker-generate-ssl-certificates/ Using Docker to Generate SSL Certificates]
# Add a line DOCKER_OPTS="-g /home/brb/Docker"
* [https://medium.com/@mannycodes/configure-self-signed-ssl-for-nginx-docker-from-a-scratch-7c2bcd5478c6 Configure Self-Signed SSL For Nginx Docker From A Scratch]
</syntaxhighlight>
* [https://smithtalkstech.com/2018/04/25/creating-a-self-signed-ssl-certificate-for-local-docker-development/ Creating a self-signed SSL certificate for local Docker development]
Then after running ''sudo service docker.io restart'' and then a simple pull '''sudo docker pull rocker/r-base''' or '''sudo docker run --rm -ti rocker/r-base''' (the Dockerfile of r-base is available on [https://github.com/rocker-org/rocker/blob/master/r-base/Dockerfile github.com], '''--rm''' option means Automatically remove the container when it exits), we will see something like this:
<syntaxhighlight lang='bash'>
$ docker run --rm -ti rocker/r-base
$ docker images
$ docker -v
Docker version 1.0.1, build 990021a


== traefik: The Cloud Native Application Proxy ==
$ docker -D info | grep Root
* https://traefik.io/traefik/
Root Dir: /home/brb/Docker/aufs
* [https://www.digitalocean.com/community/tutorials/how-to-use-traefik-as-a-reverse-proxy-for-docker-containers-on-ubuntu-18-04 How To Use Traefik as a Reverse Proxy for Docker Containers on Ubuntu 18.04]
</syntaxhighlight>
* [https://www.howtoforge.com/how-to-install-and-use-traefik-as-a-reverse-proxy-with-docker-on-centos-8/ How to Install and Use Traefik as a Reverse Proxy with Docker on CentOS 8]
* [https://www.digitalocean.com/community/tutorials/how-to-use-traefik-v2-as-a-reverse-proxy-for-docker-containers-on-ubuntu-20-04 How To Use Traefik v2 as a Reverse Proxy for Docker Containers on Ubuntu 20.04]
* [https://medium.com/accesto/docker-reverse-proxy-using-traefik-2657c0086a3d Docker reverse proxy using Traefik]
* [https://blog.eleven-labs.com/en/using-traefik-as-a-reverse-proxy/ USING TRAEFIK AS A REVERSE PROXY]
* [https://youtu.be/N5EmluXSbEg How to Install Traefik 2 on OMV and Docker] DB Tech 2020. Cloudflare, Portainer. Airsonic.
* [https://youtu.be/liV3c9m_OX8 Put Wildcard Certificates and SSL on EVERYTHING - Traefik Tutorial] Apr 2021
* Raspberry Pi
** [https://www.alexhyett.com/traefik-vs-nginx-docker-raspberry-pi Traefik vs Nginx for Reverse Proxy with Docker on a Raspberry Pi]
** [https://codecaptured.com/blog/self-hosting-pi-hole-with-docker-and-traefik/ Self-Hosting Pi-hole with Docker and Traefik]
** [https://blog.pankajgarg.com/helloaspnetcoreonpi/ Running ASP.NET core web application on Raspberry Pi]
* [https://youtu.be/liV3c9m_OX8 Put Wildcard Certificates and SSL on EVERYTHING - Traefik Tutorial] (video)


== Nginx proxy manager ==
=== Consuming Docker system events ===
* https://nginxproxymanager.com/
<syntaxhighlight lang='bash'>
* [https://www.the-digital-life.com/nginx-proxy-manager/ NGINX Proxy Manager – How-To Installation and Configuration]
# Open a new terminal
* [https://youtu.be/CSbgLBcIuwE Access your internal websites! Nginx Reverse Proxy in Home Assistant]
docker system events
* [https://www.howtoforge.com/how-to-install-and-use-nginx-proxy-manager/ How to Install and Use Nginx Proxy Manager with Docker] 2022
# This command is a blocking command.  
* [https://www.the-digital-life.com/nginx-proxy-manager/ NGINX Proxy Manager – How-To Installation and Configuration] the-digital-life
# Thus, when you execute it in your terminal session the according session is blocked.
* https://hub.docker.com/r/jlesage/nginx-proxy-manager, [https://github.com/jlesage/docker-nginx-proxy-manager Github]
* [https://dev.to/domysee/setting-up-a-reverse-proxy-with-nginx-and-docker-compose-29jg Setting up a Reverse-Proxy with Nginx and docker-compose]
* [https://linoxide.com/containers/setup-nginx-reverse-proxy-docker/ How to Setup NGINX as Reverse Proxy Using Docker]. It works.
** Download the code from https://github.com/a-magdy/nginx-reverse-proxy-docker.
** On the step of modifying /etc/hosts, change the IP address from 172.31.30.78 to 127.0.0.1 for site1.test and site2.test. Or I can use '''docker inspect XXXX | grep IPAddress''' to find out the IP for site1_default and site2_default (these two names are defined in <docker-compose.yml>).
** Before creating proxy container, though two web services are up and running inside container, we still cannot test site1.test and site2.test.
** docker-compose build shows successful build. But where is the image?
** ''curl site1.test'' and ''curl site2.test'' work fine.
** We can also use a browser to check these two URLs. For https it still works though FF gives warnings for self signed certificates.
** '''nmap localhost''' will show ports 80 & 443 are open.
* [https://www.freecodecamp.org/news/docker-nginx-letsencrypt-easy-secure-reverse-proxy-40165ba3aee2/ How to set up an easy and secure reverse proxy with Docker, Nginx]
* [http://littlebigextra.com/install-nginx-reverse-proxy-server-docker/ How to install Nginx as a reverse proxy server with Docker]. Note that http://microservice1:8080;  needs to be changed to reflect the true IP whether it is from a docker container or not. Also it does not work when I modify the --link option to use site1_app_1 and site2_app_1.
{{Pre}}
docker: Error response from daemon: Cannot link to /site1_app_1, as it does not belong to the default network.
</pre>
* [https://phoenixnap.com/kb/docker-nginx-reverse-proxy How to Deploy NGINX Reverse Proxy on Docker] (multiple web services)
* [https://www.howtoforge.com/how-to-install-and-use-portainer-for-docker-management-with-nginx-proxy-manager/ How to Install and Use Portainer for Docker management with Nginx Proxy Manager]


== Running multiple web applications on a Docker host ==
# Open another terminal
* https://medium.com/@jmarhee/running-multiple-web-applications-on-a-docker-host-with-apache-85f673f02803. Tips: Enable proxy module in Apache. In the ''VirtualHost'' file, specify '''ProxyPass''' with a port number. No need to specify the DocumentRoot.
docker container run --rm alpine echo "Hello World"
* https://medium.com/@francoisromain/host-multiple-websites-with-https-inside-docker-containers-on-a-single-server-18467484ab95. Nginx reverse-proxy is used.
</syntaxhighlight>
* https://blog.florianlopes.io/host-multiple-websites-on-single-host-docker/. [https://github.com/jwilder/nginx-proxy jwilder/nginx-proxy] is used. No need (and should not to avoid a conflict of port 80) to install Nginx <syntaxhighlight lang='bash'>
docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock jwilder/nginx-proxy


sudo nano /etc/hosts # add blog.domain.com and jenkins.domain.com for our testing purpose
=== Monitor tools ===
* [https://www.2daygeek.com/ctop-a-command-line-tool-for-container-monitoring-and-management-in-linux/# cTop – A Command-Line Tool For Container Monitoring And Management In Linux], [https://github.com/bcicen/ctop ctop]


docker run -d --expose 80 -e VIRTUAL_HOST=blog.domain.com wordpress
== [https://docs.docker.com/machine/overview/ Docker Machine] ==
docker run -d --name jenkinsci --expose 8080 -e VIRTUAL_HOST=jenkins.domain.com -e VIRTUAL_PORT=8080 jenkins
Docker Machine is a tool that lets you
</syntaxhighlight>
* Install Docker Engine on virtual hosts. You can use Machine (a unified way) to create Docker hosts on your local Mac or Windows box, on your company network, in your data center, or on cloud providers like Azure, AWS, or Digital Ocean. See the comment on [https://sreeninet.wordpress.com/2015/05/31/docker-machine/ here].
** Use VIRTUAL_PORT if there are multiple ports associated with a container
* Provision and manage multiple remote Docker hosts
** Use VIRTUAL_HOST if there are multiple domains associated with a container
* Provision Swarm clusters
** SSL and et al


== Authentication: Authelia ==
Docker machine is not installed in Linux when you install Docker. See the instruction on [https://docs.docker.com/machine/install-machine/ here] to install it.
[https://www.youtube.com/watch?v=4UKOh3ssQSU Additional Self-Hosted Security with Authelia on NGINX Proxy Manager] (video)


== GUI apps ==
My feeling is if we just want to play Docker on a local Linux machine, we don't really need to use Docker Machine (it just make life more complicated). But if we are working on Mac/Windows or we want to work on clouds or test on VirtualBox, we shall use Docker machines.
* [https://www.cloudsavvyit.com/10520/how-to-run-gui-applications-in-a-docker-container/ How to Run GUI Applications in a Docker Container]
* https://github.com/mviereck/x11docker/ which was used by [https://github.com/ehough/docker-kodi Docker-kodi]
* https://pelle.io/2014/07/11/delivering-gui-applications-with-docker/ Forward X11 approach
* https://linuxmeerkat.wordpress.com/2014/10/17/running-a-gui-application-in-a-docker-container/ Forward X11
* http://fabiorehm.com/blog/2014/09/11/running-gui-apps-with-docker/ Share X11 socket
* https://github.com/rogaha/docker-desktop  Xpra + Xephyr
* https://github.com/fcwu/docker-ubuntu-vnc-desktop VNC approach


=== Docker-OSX ===
[https://youtu.be/OWhhOQAiGt0 Use Docker-machine to Create Docker Servers]. Compare the Docker images on the local machine (server 1) & a new host (server 2) created by '''docker-machine'''. Question: 1. how to tell we are in the host/machine environment? 2. how to exit the host environment after we use ''eval $() command? docker-machine stop MachineName.
https://github.com/sickcodes/Docker-OSX
<pre>
 
$ docker-machine help
== Pruning unused resources ==
$ docker-machine create --driver=virtualbox test
* Prune containers
# Follow its hint on the output, issue the following command
<syntaxhighlight lang='bash'>
$ docker-machine env test
docker container prune # remove all containers that are not in ''running'' status
# Follow its hint on the output, issue the following command
                      # Docker will ask for confirmation before deleting the containers
$ eval$(docker-machine env test) # will configure the docker CLI to connect to this docker machine 'test'
                                # This is equivalent to running 4 export commands on the command line
$ docker-machine ls  # Very useful
$ docker-machine stop test
$ docker-machine ip test
$ docker-machine start test
$ docker-machine rm test
</pre>


docker container prune -f
[https://youtu.be/rnaLmSkZfKk Play Docker Machine on Mac with Virtualbox]. Docker can be used to create a virtual machine just like Vagrant.
docker container rm -f $(docker container ls -aq) # remove even the running containers
<pre>
</syntaxhighlight>
$ docker-machine create -d virtualbox demo
* Prune images
$ docker-machine ls
<syntaxhighlight lang='bash'>
docker images prune # unused image layers
</syntaxhighlight>
* Prune volumes
<syntaxhighlight lang='bash'>
docker volume prune # unused volumes by at least one container


docker volume prune --filter 'label=demo'
# first way to access a Docker host
docker volume prune --filter 'label=demo' --filter 'label=test'
$ docker-machine ssh demo
</syntaxhighlight>
docker@demo:~$ docker images # empty for now
* Prune networks
<syntaxhighlight lang='bash'>
docker network prune
</syntaxhighlight>
* Prune everything
<syntaxhighlight lang='bash'>
docker system prune
</syntaxhighlight>


== Plugins ==
# second way to access
[https://www.cloudsavvyit.com/15066/how-to-manage-docker-engine-plugins/ How to Manage Docker Engine Plugins]
$ docker-machine env demo
$ eval $(docker-machine env demo)
$ docker version
</pre>


== Misc ==
[http://rancher.com/rancher-os/ RancherOS demo video] used the '''docker-machine''' command to pull and run the RancherOS.
=== LXC (raw Linux containers) ===
<pre>
* https://help.ubuntu.com/lts/serverguide/lxc.html
docker-machine create -d virtualbox --virtualbox-boot2docker-url https://releases.rancher.com/os/latest/rancheros.iso demo
* https://help.ubuntu.com/community/LXC
docker-machine ssh demo
* https://askubuntu.com/questions/293275/what-is-lxc-and-how-to-get-started
ps
* [https://www.cyberciti.biz/faq/how-to-install-lxd-container-hypervisor-on-ubuntu-16-04-lts-server/ Setup Linux Container with LXC on Ubuntu 16.04]
docker ps
* [http://en.community.dell.com/techcenter/os-applications/w/wiki/6950.lxc-containers-in-ubuntu-server-14-04-lts LXC containers in Ubuntu Server 14.04 LTS]
sudo system-docker ps
* [https://blog.simos.info/trying-out-lxd-containers-on-our-ubuntu/ Trying out LXD containers on our Ubuntu]


==== LXC vs Docker ====
sudo ros help
* https://diveintodocker.com/blog/why-i-got-started-with-docker
sudo ros console list
* https://unix.stackexchange.com/questions/254956/what-is-the-difference-between-docker-lxd-and-lxc and https://i.stack.imgur.com/a5Neb.png
sudo ros console switch ubunu
apt-get help
</pre>
 
== Docker Compose <docker-compose.yaml> ==
Docker Compose can help us out as it allows us to specify a single file in which we can define our entire environment structure and run it with a single command (much like a Vagrantfile works).  


=== Vagrant vs Docker ===
* https://docs.docker.com/compose/ (the example will give an error when "RUN pip install -r requirements.txt")
* http://stackoverflow.com/questions/16647069/should-i-use-vagrant-or-docker-io-for-creating-an-isolated-environment
*# app.py
*# requirements.txt
*# Dockerfile
*# docker-compose.yml
* Some top-level '''keys''': version, services, networks, volumes
* [https://stackoverflow.com/questions/38507446/docker-dockerfile-vs-docker-compose-yml Dockerfile vs docker-compose.yml]
* A simple example of running [https://www.tutorialspoint.com/docker/docker_compose.htm nginx & mysqsl]
* [https://youtu.be/Qw9zlE3t8Ko Docker Compose in 12 Minutes]
* https://deliciousbrains.com/vagrant-docker-wordpress-development/
* https://deliciousbrains.com/vagrant-docker-wordpress-development/
** Vagrant is easier to understand and is easier to get up and running but can be very resource intensive (in terms of RAM and space).
* https://github.com/kristophjunge/docker-mediawiki
** Docker’s architecture is harder to understand and can be harder to get up and running but is much faster, uses much less CPU and RAM and potentially uses much less space than Vagrant VM’s.
* [https://www.howtoforge.com/tutorial/docker-guide-dockerizing-python-django-application/ Docker Guide: Dockerizing Python Django Application] (cannot follow)
* https://youtu.be/9QGkJvbLpRA?t=3m22s
* Examples:
** Docker uses container technology while vagrant uses virtual machines.
** [https://github.com/haroldtreen/epub-press EpubPress] local server
** If security is a concern, use vagrant and virtual machine
** Running [https://github.com/nextcloud/docker nextcloud], [https://blog.ouseful.info/2017/06/16/rolling-your-own-jupyter-and-rstudio-data-analysis-environment-around-apache-drill-using-docker-compose/ Jupyter and RStudio]
** For speeding development and sharing, use Docker.
** [https://github.com/dceoy/docker-rstudio-server Rstudio]
** Most teams use both to run a smooth operation


=== Date/Time zone ===
=== Download binary ===
* http://tedwise.com/2015/05/02/setting-the-timezone-in-a-docker-image/
* https://github.com/docker/compose/releases
* https://stackoverflow.com/questions/22800624/will-docker-container-auto-sync-time-with-the-host-machine
* [https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-compose-on-ubuntu-20-04 How To Install and Use Docker Compose on Ubuntu 20.04]
{{Pre}}
wget https://github.com/docker/compose/releases/download/v2.6.0/docker-compose-linux-x86_64
sudo mv docker-compose-linux-x86_64 /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose
docker-compose --version
</pre>
 
=== Composerize ===
[https://ostechnix.com/convert-docker-run-commands-into-docker-compose-files/ Convert Docker Run Commands Into Docker-Compose Files]
 
=== An example from 'Fundamentals of Docker' ===
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
docker run --rm -t -i -v /etc/localtime:/etc/localtime:ro ubuntu date
git clone https://github.com/fundamentalsofdocker/labs.git
cd labs/ch08
docker-compose up
# Open http://localhost:3000/pet
</syntaxhighlight>
</syntaxhighlight>
* https://serverfault.com/questions/683605/docker-container-time-timezone-will-not-reflect-changes
The images do not show up:( The terminal shows what has happened under the hood. So the problem is the http links for images do not exist.


=== Access the internet from the container ===
We can also run the application in the background
Run the container with the '--net=host' option
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
sudo docker run --net=host -it ubuntu /bin/bash
docker-compose up -d
</syntaxhighlight>
</syntaxhighlight>


=== How to transfer/copy an image to another host ===
To stop and clean up the application,
[https://stackoverflow.com/a/23938978 How to copy Docker images from one host to another without using a repository]
<syntaxhighlight lang='bash'>
<syntaxhighlight lang='bash'>
# Step 1: save the Docker image as a tar file:
docker-compose down
docker save -o <path for generated tar file> <image name>
</syntaxhighlight>


# Step 2: copy your image to a new system with regular file transfer tools such as cp or scp.
If we also want to remove the volume for the database
 
<syntaxhighlight lang='bash'>
# Step 3: After that you will have to load the image into Docker:
docker volume rm ch08_pets-data
docker load -i <path to image tar file>
</syntaxhighlight>
</syntaxhighlight>
The tar file size is the same as what we get from 'docker image'. If we use the 'gzip' utility, it can reduce the file size (e.g 2.7GB to 1.1GB).


Or https://stackoverflow.com/a/39716019
=== An example from "How to Setup NGINX as Reverse Proxy Using Docker" ===
<syntaxhighlight lang='bash'>
See [[#Nginx_reverse_proxy|here]]. Only nginx is used.
# Step 1:
docker save docker-image-name | gzip > my-image.tar.gz
# Step 3:
docker load < my-image.tar.gz
</syntaxhighlight>


=== Where are Docker images stored on the host: /var/lib/docker ===
=== An example from "Docker Deep Dive" (flask + redis) ===
* http://blog.thoward37.me/articles/where-are-docker-images-stored/
'''Note''' that on [https://docs.docker.com/compose/gettingstarted/#step-7-update-the-application Get started with Docker Compose] it mounts the current directory to ''/code'' inside the container. So after we modify ''app.py'', we don't need to copy it to the container.
* http://stackoverflow.com/questions/19234831/where-are-docker-images-stored-on-the-host-machine
* https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-storage-driver
* http://stackoverflow.com/questions/21016210/function-of-docker-directory-structure-in-var-lib-docker
* [https://foxutech.com/manage-docker-images-local-disk/ How to Manage Docker images on local disk]


The default is '''/var/lib/docker'''. The location can be changed by modifying the file '''/etc/default/docker'''. Three options if we are tight on the disk space.
Another one [https://takacsmark.com/docker-compose-tutorial-beginners-by-example-basics/ Docker compose tutorial for beginners by example]
<syntaxhighlight lang='bash'>
$ git clone https://github.com/nigelpoulton/counter-app.git
$ cd counter-app
$ ls
app.py  docker-compose.yml  Dockerfile  README.md  requirements.txt


'''1. Create a softlinks''' for the Docker data directory (/var/lib/docker) and for /var/lib/docker/tmp as described at [https://docs.docker.com/engine/reference/commandline/dockerd/#miscellaneous-options miscellaneous-options]. See [https://stackoverflow.com/a/40919928 this]. See [https://stackoverflow.com/a/40192707 for how to stop docker daemon] on different OS.
$ cat requirements.txt
<syntaxhighlight lang='bash'>
flask
sudo service docker stop  # or sudo systemctl stop docker
sudo mv /var/lib/docker /a/new/location
sudo ln -s /a/new/location /var/lib/docker # Create a symbolic link
sudo service docker start  # or sudo systemctl start docker
</syntaxhighlight>


'''2. Change the default location to another place'''. For example,
$ cat Dockerfile
<syntaxhighlight lang='bash'>
FROM python:3.4-alpine
sudo nano /etc/default/docker
ADD . /code
# Add a line DOCKER_OPTS="-g /home/brb/Docker"
WORKDIR /code
</syntaxhighlight>
RUN pip install -r requirements.txt
Then after running ''sudo service docker.io restart'' and then a simple pull '''sudo docker pull rocker/r-base''' or '''sudo docker run --rm -ti rocker/r-base''' (the Dockerfile of r-base is available on [https://github.com/rocker-org/rocker/blob/master/r-base/Dockerfile github.com], '''--rm''' option means Automatically remove the container when it exits), we will see something like this:
CMD ["python", "app.py"]
<syntaxhighlight lang='bash'>
$ docker run --rm -ti rocker/r-base
$ docker images
$ docker -v
Docker version 1.0.1, build 990021a


$ docker -D info | grep Root
$ cat docker-compose.yml
Root Dir: /home/brb/Docker/aufs
version: "3.5"
</syntaxhighlight>
services:
 
  web-fe:
=== Consuming Docker system events ===
    build: .
<syntaxhighlight lang='bash'>
    command: python app.py
# Open a new terminal
    ports:
docker system events
      - target: 5000
# This command is a blocking command.
        published: 5000
# Thus, when you execute it in your terminal session the according session is blocked.
    networks:
      - counter-net
    volumes:
      - type: volume
        source: counter-vol
        target: /code
  redis:
    image: "redis:alpine"
    networks:
      counter-net:


# Open another terminal
networks:
docker container run --rm alpine echo "Hello World"
  counter-net:
</syntaxhighlight>


=== Monitor tools ===
volumes:
* [https://www.2daygeek.com/ctop-a-command-line-tool-for-container-monitoring-and-management-in-linux/# cTop – A Command-Line Tool For Container Monitoring And Management In Linux], [https://github.com/bcicen/ctop ctop]
  counter-vol:


== [https://docs.docker.com/machine/overview/ Docker Machine] ==
$ docker-compose up &
Docker Machine is a tool that lets you
* Install Docker Engine on virtual hosts. You can use Machine (a unified way) to create Docker hosts on your local Mac or Windows box, on your company network, in your data center, or on cloud providers like Azure, AWS, or Digital Ocean. See the comment on [https://sreeninet.wordpress.com/2015/05/31/docker-machine/ here].
* Provision and manage multiple remote Docker hosts
* Provision Swarm clusters


Docker machine is not installed in Linux when you install Docker. See the instruction on [https://docs.docker.com/machine/install-machine/ here] to install it.
$ docker container ls


My feeling is if we just want to play Docker on a local Linux machine, we don't really need to use Docker Machine (it just make life more complicated). But if we are working on Mac/Windows or we want to work on clouds or test on VirtualBox, we shall use Docker machines.
$ docker network ls
NETWORK ID          NAME                    DRIVER              SCOPE
2acef6dabde6        bridge                  bridge              local
a2d42bc482ff        counterapp_counter-net  bridge              local
e1e093b64282        host                    host                local
7ecd0a6a9ebd        none                    null                local


[https://youtu.be/OWhhOQAiGt0 Use Docker-machine to Create Docker Servers]. Compare the Docker images on the local machine (server 1) & a new host (server 2) created by '''docker-machine'''. Question: 1. how to tell we are in the host/machine environment? 2. how to exit the host environment after we use ''eval $() command? docker-machine stop MachineName.
# Open the browser http://localhost:5000
<pre>
$ docker-compose ps
$ docker-machine help
      Name                      Command              State          Ports       
$ docker-machine create --driver=virtualbox test
-------------------------------------------------------------------------------------
# Follow its hint on the output, issue the following command
counterapp_redis_1    docker-entrypoint.sh redis ...  Up      6379/tcp             
$ docker-machine env test
counterapp_web-fe_1  python app.py                    Up      0.0.0.0:5000->5000/tcp
# Follow its hint on the output, issue the following command
$ eval$(docker-machine env test) # will configure the docker CLI to connect to this docker machine 'test'
                                # This is equivalent to running 4 export commands on the command line
$ docker-machine ls  # Very useful
$ docker-machine stop test
$ docker-machine ip test
$ docker-machine start test
$ docker-machine rm test
</pre>


[https://youtu.be/rnaLmSkZfKk Play Docker Machine on Mac with Virtualbox]. Docker can be used to create a virtual machine just like Vagrant.
$ docker-compose stop
<pre>
$ docker-compose ps
$ docker-machine create -d virtualbox demo
# We can see stopping a Compose app does not delete the application
$ docker-machine ls


# first way to access a Docker host
$ docker container ls -a
$ docker-machine ssh demo
$ docker-compose rm    # delete a stopped Compose app
docker@demo:~$ docker images # empty for now
                        # images, volumes and source code remain
 
$ docker-compose restart
# second way to access
                        # If you made changes to your Compose app since stopping,
$ docker-machine env demo
                        # these changes will not appear in the restarted app.
$ eval $(docker-machine env demo)
                        # You need to re-deploy the app to get the changes.
$ docker version
$ docker-compose ps
</pre>
$ docker-compose down  # stop and delete the app
                        # images, volumes and source code remain
$ docker-compose down --volumes # remove the data volume used by the Redis container
$ docker-compose up -d
$ docker volume ls
$ docker-compose
 
# We can make changes to files in the volume, from the host side,
# and have them reflected immediately in the app.
$ nano app.py  # do some changes
$ docker volume inspect counterapp_counter-vol | grep Mount
$ sudo cp app.py \
  /var/lib/docker/volumes/counterapp_counter-vol/_data/app.py
# Our changes should be reflected


[http://rancher.com/rancher-os/ RancherOS demo video] used the '''docker-machine''' command to pull and run the RancherOS.
$ docker-compose --help
<pre>
</syntaxhighlight>
docker-machine create -d virtualbox --virtualbox-boot2docker-url https://releases.rancher.com/os/latest/rancheros.iso demo
docker-machine ssh demo
ps
docker ps
sudo system-docker ps


sudo ros help
 
sudo ros console list
=== Docker-Compose persistent data MySQL ===
sudo ros console switch ubunu
https://stackoverflow.com/questions/39175194/docker-compose-persistent-data-mysql
apt-get help
 
=== Connect to Docker daemon over ssh using docker-compose ===
[https://medium.com/@sujaypillai/dockertips-connect-to-docker-daemon-over-ssh-using-docker-compose-f4b189dd8951 #DockerTips: Connect to Docker daemon over ssh using docker-compose]
 
=== Dockerfile + docker-compose ===
[https://stackoverflow.com/a/29487120 Docker Compose vs. Dockerfile - which is better?]
 
The Compose file describes the container in its running state, leaving the details on how to build the container to Dockerfiles.
 
=== How to deploy on remote Docker hosts with docker-compose ===
[https://www.docker.com/blog/how-to-deploy-on-remote-docker-hosts-with-docker-compose/ How to deploy on remote Docker hosts with docker-compose]
 
=== logs ===
<pre>
docker-compose logs -f
# Ctrl + c
</pre>
</pre>


== Docker Compose <docker-compose.yaml> ==
== Package CLI Applications ==
Docker Compose can help us out as it allows us to specify a single file in which we can define our entire environment structure and run it with a single command (much like a Vagrantfile works).
[https://www.cloudsavvyit.com/15713/how-to-use-docker-to-package-cli-applications/ How to Use Docker to Package CLI Applications]


* https://docs.docker.com/compose/ (the example will give an error when "RUN pip install -r requirements.txt")
== Stack ==
*# app.py
* https://www.composerize.com/
*# requirements.txt
* [https://youtu.be/-ttZjGBkLL8 Export Docker Container Settings as Docker Compose Stack], [https://github.com/Red5d/docker-autocompose docker-autocompose] (only x86)
*# Dockerfile
*# docker-compose.yml
* Some top-level '''keys''': version, services, networks, volumes
* [https://stackoverflow.com/questions/38507446/docker-dockerfile-vs-docker-compose-yml Dockerfile vs docker-compose.yml]
* A simple example of running [https://www.tutorialspoint.com/docker/docker_compose.htm nginx & mysqsl]
* [https://youtu.be/Qw9zlE3t8Ko Docker Compose in 12 Minutes]
* https://deliciousbrains.com/vagrant-docker-wordpress-development/
* https://github.com/kristophjunge/docker-mediawiki
* [https://www.howtoforge.com/tutorial/docker-guide-dockerizing-python-django-application/ Docker Guide: Dockerizing Python Django Application] (cannot follow)
* Examples:
** [https://github.com/haroldtreen/epub-press EpubPress] local server
** Running [https://github.com/nextcloud/docker nextcloud], [https://blog.ouseful.info/2017/06/16/rolling-your-own-jupyter-and-rstudio-data-analysis-environment-around-apache-drill-using-docker-compose/ Jupyter and RStudio]
** [https://github.com/dceoy/docker-rstudio-server Rstudio]


=== An example from 'Fundamentals of Docker' ===
== Docker app ==
<syntaxhighlight lang='bash'>
Docker App is an experimental Docker feature which lets you build and publish application stacks consisting of multiple containers. It aims to let you share '''Docker Compose''' stacks with the same ease of use as regular Docker containers.
git clone https://github.com/fundamentalsofdocker/labs.git
cd labs/ch08
docker-compose up
# Open http://localhost:3000/pet
</syntaxhighlight>
The images do not show up:( The terminal shows what has happened under the hood. So the problem is the http links for images do not exist.


We can also run the application in the background
[https://www.cloudsavvyit.com/10673/how-to-use-docker-app-to-containerise-an-entire-application-stack/ How to Use 'Docker App' to Containerise an Entire Application Stack]
<syntaxhighlight lang='bash'>
docker-compose up -d
</syntaxhighlight>


To stop and clean up the application,
== Docker Swarm ==
<syntaxhighlight lang='bash'>
* https://www.linux.com/learn/how-use-docker-machine-create-swarm-cluster
docker-compose down
* [https://www.howtoforge.com/tutorial/ubuntu-docker-swarm-cluster/ How Setup and Configure Docker Swarm Cluster on Ubuntu]
</syntaxhighlight>
* [https://www.cloudsavvyit.com/13049/what-is-docker-swarm-mode-and-when-should-you-use-it/ What is Docker Swarm Mode and When Should You Use It?]


If we also want to remove the volume for the database
== Security ==
<syntaxhighlight lang='bash'>
* [https://cloudberry.engineering/article/dockerfile-security-best-practices/ Docker Security Best Practices from the Dockerfile]
docker volume rm ch08_pets-data
* [https://www.cloudsavvyit.com/12631/how-to-secure-sensitive-data-with-docker-compose-secrets/ How to Secure Sensitive Data With Docker Compose Secrets]
</syntaxhighlight>
 
== [https://mobyproject.org/ Moby Project] ==
[https://www.infoworld.com/article/3193904/containers/what-is-dockers-moby-project.html What is Docker's Moby Project?]


=== An example from "How to Setup NGINX as Reverse Proxy Using Docker" ===
== Windows container ==
See [[#Nginx_reverse_proxy|here]]. Only nginx is used.
[https://stackoverflow.com/questions/45380972/how-can-i-run-a-docker-windows-container-on-osx How can I run a docker windows container on osx?]


=== An example from "Docker Deep Dive" (flask + redis) ===
== When Not to Use Docker ==
'''Note''' that on [https://docs.docker.com/compose/gettingstarted/#step-7-update-the-application Get started with Docker Compose] it mounts the current directory to ''/code'' inside the container. So after we modify ''app.py'', we don't need to copy it to the container.
[https://www.cloudsavvyit.com/15446/when-not-to-use-docker-cases-where-containers-dont-help/ When Not to Use Docker: Cases Where Containers Don’t Help]


Another one [https://takacsmark.com/docker-compose-tutorial-beginners-by-example-basics/ Docker compose tutorial for beginners by example]
= GUI/TUI interface manager =
<syntaxhighlight lang='bash'>
== [https://github.com/moncho/dry Dry] ==
$ git clone https://github.com/nigelpoulton/counter-app.git
[https://www.2daygeek.com/dry-an-interactive-cli-manager-for-docker-containers/ Dry – An Interactive CLI Manager For Docker Containers]. The TUI is built on top of [https://github.com/gizak/termui termui]; a cross-platform, easy-to-compile, and fully-customizable terminal dashboard. It is inspired by [https://github.com/yaronn/blessed-contrib blessed-contrib], but purely in Go.
$ cd counter-app
$ ls
app.py  docker-compose.yml  Dockerfile  README.md  requirements.txt


$ cat requirements.txt
== LazyDocker (TUI) ==
flask
[https://www.linuxuprising.com/2019/07/lazydocker-new-docker-and-docker.html?m=1 LazyDocker: New Docker And Docker Compose Terminal UI], [https://github.com/jesseduffield/lazydocker Github]


$ cat Dockerfile
It works on ARM devices too.
FROM python:3.4-alpine
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt
CMD ["python", "app.py"]


$ cat docker-compose.yml
== Dockly (TUI) ==
version: "3.5"
[https://www.ostechnix.com/dockly-manage-docker-containers-from-terminal/ Dockly – Manage Docker Containers From Terminal]
services:
  web-fe:
    build: .
    command: python app.py
    ports:
      - target: 5000
        published: 5000
    networks:
      - counter-net
    volumes:
      - type: volume
        source: counter-vol
        target: /code
  redis:
    image: "redis:alpine"
    networks:
      counter-net:


networks:
== DockStation ==
  counter-net:
It is not open source. It works with remote Docker containers.


volumes:
* [https://github.com/DockStation/dockstation DockStation]
  counter-vol:
* [https://www.upnxtblog.com/index.php/2018/01/17/top-6-gui-tools-for-managing-docker-environments/ TOP 6 GUI tools for managing Docker environments] 2018
* [https://www.how2shout.com/tools/4-best-docker-gui-tools-to-manage-containers-graphically.html 4 Best Docker GUI tools to manage containers graphically] 2019


$ docker-compose up &
== DockSTARTer: get started with home server apps running in Docker ==
* https://dockstarter.com/
* [https://www.makeuseof.com/tag/setup-linux-media-server/ How to Set Up a Linux Media Server in Under One Hour]


$ docker container ls
== [https://portainer.io/ Portainer]* (nice) ==
 
<ul>
$ docker network ls
<li>[https://github.com/portainer/portainer/issues/5406 Hardware minimum requirements] 100MB RAM. That's why 1GB ram of Raspberry Pi works fine.
NETWORK ID          NAME                    DRIVER              SCOPE
<li>[https://docs.portainer.io/start/install/server/docker/linux Install], [https://docs.portainer.io/ Documentation]
2acef6dabde6        bridge                  bridge              local
<pre>
a2d42bc482ff        counterapp_counter-net   bridge              local
docker volume create portainer_data
e1e093b64282        host                    host                local
docker run -d -p 8000:8000 -p 9443:9443 \
7ecd0a6a9ebd        none                    null                local
  --name portainer \
 
  --restart=always \
# Open the browser http://localhost:5000
  -v /var/run/docker.sock:/var/run/docker.sock \
$ docker-compose ps
   -v portainer_data:/data portainer/portainer-ce:latest
      Name                      Command              State          Ports       
</pre>
-------------------------------------------------------------------------------------
By default, Portainer Server will expose the UI over port 9443 and expose a TCP tunnel server over port 8000. The latter is optional and is only required if you plan to use the Edge compute features with Edge agents.
counterapp_redis_1    docker-entrypoint.sh redis ...  Up      6379/tcp             
</li>
counterapp_web-fe_1  python app.py                    Up      0.0.0.0:5000->5000/tcp
<li>Access https://localhost:9443 </li>
 
<li>Portainer itself is a docker application. </li>
$ docker-compose stop
<li>[https://docs.portainer.io/advanced/reset-admin Reset the admin user's password].</li>
$ docker-compose ps
<li>[https://youtu.be/M365jgJ0O2E How to Update Portainer Fast, Simple, and Easy Guide]. docker stop + docker rm + docker rmi + docker run.
# We can see stopping a Compose app does not delete the application
</li>
 
<li>[https://dbtechreviews.com/2020/08/update-portainer-to-version-2-0-super-easy/ Update Portainer to Version 2.0 – Super Easy!]. When the first time accessing http://localhost:9000, you need to create a password (at least 8 characters long) for the default user "admin".
$ docker container ls -a
{{Pre}}
$ docker-compose rm    # delete a stopped Compose app
$ docker volume create portainer_data
                        # images, volumes and source code remain
$ docker run -d -p 9000:9000 -p 8000:8000 --name portainer --restart always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce
$ docker-compose restart
</pre>
                        # If you made changes to your Compose app since stopping,
* [https://youtu.be/2oi4IQF7VnE Raspberry Pi Home Server Episode 5: Remote Access with NGINX Proxy Manager]
                        # these changes will not appear in the restarted app.
* [https://youtu.be/ji0kgXhXR6g Raspberry Pi Home Server Episode 8: BitWardenRS - Password Manager with Remote Access] (video)
                        # You need to re-deploy the app to get the changes.
* [https://dbtechreviews.com/2020/07/install-nextcloud-on-a-raspberry-pi-4-with-openmediavault-and-docker/ Install NextCloud on a Raspberry Pi 4 with OpenMediaVault and Docker]
$ docker-compose ps
</li>
$ docker-compose down  # stop and delete the app
<li>Update from 2.11 to 2.13 (The password must be at least 12 characters long)
                        # images, volumes and source code remain
<ul>
$ docker-compose down --volumes # remove the data volume used by the Redis container
<li>Step 1: [https://dbtechreviews.com/2021/08/how-to-update-portainer-to-the-newest-version/ How to Update Portainer to the Newest Version]
$ docker-compose up -d
<pre>
$ docker volume ls
sudo docker stop portainer && sudo docker rm portainer
$ docker-compose
docker pull portainer/portainer-ce:latest
 
</pre>
# We can make changes to files in the volume, from the host side,
</li>
# and have them reflected immediately in the app.
<li>Step 2: [https://docs.portainer.io/start/upgrade/docker Upgrading on Docker Standalone]
$ nano app.py  # do some changes
{{Pre}}
$ docker volume inspect counterapp_counter-vol | grep Mount
docker run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce:latest
$ sudo cp app.py \
</pre>
  /var/lib/docker/volumes/counterapp_counter-vol/_data/app.py
</li>
# Our changes should be reflected
</ul>
</ul>
* [https://github.com/portainer/portainer-docs/issues/91 Why port 8000 is needed to be published?], [https://forums.portainer.io/t/what-port-8000-used-for-do-i-need-to-expose-it/210 What port 8000 used for? Do I need to expose it?]
* [https://dzone.com/articles/a-comparison-of-docker-guis A Comparison of Docker GUIs]. A username/password is required to access the page unless we use the '''--no-auth''' option; see [https://portainer.readthedocs.io/en/stable/configuration.html Configuration].
* [https://www.howtoforge.com/tutorial/ubuntu-docker-portainer/ How to Manage Docker Containers using Portainer on Ubuntu 16.04]. Go to Local. It will show the status of all local stacks, containers, volumes and images. Very Cool!
* [https://www.linuxtechi.com/monitor-manage-docker-containers-portainer-part1/ Monitor and Manage Docker Containers with Portainer.io (GUI tool) – Part-1] 2019
* [https://www.cloudsavvyit.com/8911/how-to-get-started-with-portainer-a-web-ui-for-docker/ How to Get Started With Portainer, a Web UI for Docker]
* [https://www.linuxtechi.com/monitor-manage-docker-containers-portainer-io-part-2/ Monitor and Manage Docker Containers with Portainer.io (GUI tool) – Part-2]
* [https://collabnix.com/portainer-vs-rancher/ Portainer Vs Rancher]
* [https://youtu.be/XYcKmPi4McA How-to: Deploy Portainer on MicroK8s] (video)
* [https://www.portainer.io/blog/from-zero-to-production-with-fedora-coreos-portainer-and-wordpress-in-7-easy-steps From Zero to Production with Fedora CoreOS, Portainer, and WordPress in 7 Easy Steps]. Virtualbox was used


$ docker-compose --help
=== Templates ===
</syntaxhighlight>
* [https://dbtechreviews.com/2020/09/using-application-templates-in-portainer-2-0/ Using Application Templates in Portainer 2.0]
* [https://youtu.be/BwgKd6LohQo Install 80+ Docker Images In Seconds Using This Portainer App Template] (video)
* [https://www.reddit.com/r/portainer/comments/v3uyo3/best_and_most_uptodate_portainer_app_template_for/?utm_source=share&utm_medium=web2x&context=3 Best and most up-to-date Portainer app template for selfhosting?] 2022-06-03
** [https://github.com/mycroftwilde/portainer_templates mycroftwilde]
* [https://youtu.be/BwgKd6LohQo Install 80+ Docker Images In Seconds Using This Portainer App Template] (video, 2020)
** Default on my Portainer 2.0.1 (see logs for version number) https://raw.githubusercontent.com/portainer/templates/master/templates-2.0.json
** https://raw.githubusercontent.com/SelfhostedPro/selfhosted_templates/portainer-2.0/Template/template.json (working), [https://github.com/SelfhostedPro/selfhosted_templates Github]
** https://raw.githubusercontent.com/nashosted/self-hosted-template/master/template.json (working)
** Alternative: [https://github.com/Taisun-Docker/taisun taisun]


== Yacht ==
* https://yacht.sh/Installation/yacht/
* [https://youtu.be/KstIS5DstTE Yacht Installed on Docker - Portainer Alternative] (video)


=== Docker-Compose persistent data MySQL ===
== cockpit-docker ==
https://stackoverflow.com/questions/39175194/docker-compose-persistent-data-mysql
* [https://www.hostwinds.com/guide/installing-and-using-cockpit-docker-linux-vps/ Installing And Using Cockpit-Docker]
* The default port is 9090.
* Not useful for manager docker containers.
<pre>
sudo apt-get -y install cockpit-docker
 
sudo systemctl restart cockpit
</pre>
 
== [https://github.com/crosbymichael/dockerui DockerUI] (Deprecated, Development continues at Portainer) ==
https://github.com/kevana/ui-for-docker. A quick start:
# Run:  <syntaxhighlight lang='bash'>
docker run -d -p 9000:9000 --privileged \
    -v /var/run/docker.sock:/var/run/docker.sock uifd/ui-for-docker
</syntaxhighlight>  where '''-v''' means to bind mount a volume.
# Open your browser to http://<dockerd host ip>:9000
 
Note: Anyone in the local network can access the website without any authentication.
 
== Rancher ==
* https://rancher.com/quick-start/. The doc above is not good enough to follow. Search Google for tutorial or get started guide including screenshots.
* [https://www.howtoforge.com/tutorial/ubuntu-rancher-docker-container-manager/ How to Manage Docker Containers with Rancher on Ubuntu 16.04]
* [https://hackernoon.com/creating-a-scalable-application-using-docker-rancher-rancheros-cattle-5feb83a3e743 Creating A Scalable Application Using Docker + Rancher + RancherOs + Cattle]
* Initial setup video https://youtu.be/1EMW1y7529Y
* Training from Rancher Labs https://youtu.be/8K14A_CZFdI. It seems Rancher is complicated but powerful. The whole operation is like Amazon Cloud.
* [https://gist.github.com/lmmendes/fbed32a452cf02d2a1095658795cb3d2 Running Rancher locally (with two hosts) using MacOS Docker and VirtualBox]
* To allow UDP port
<syntaxhighlight lang='bash'>
$ sudo apt-get install ufw
$ sudo ufw allow 4500/udp
$ sudo ufw allow 500/udp
</syntaxhighlight>
* discoposse.com
** [http://discoposse.com/2015/11/08/rancher-part-1-installing-rancher-and-setting-access-control/ Part 1] Installing Rancher and Setting Access Control
** [http://discoposse.com/2015/11/09/rancher-part-2-adding-a-docker-host-to-rancher/ Part 2] Adding a Docker Host to Rancher
** [http://discoposse.com/2015/11/12/rancher-part-3-adding-the-dockerhub-to-our-rancher-registry/ Part 3] Adding the DockerHub to our Rancher Registry
** [http://discoposse.com/2015/11/13/rancher-part-4-using-the-catalog-example-with-glusterfs/ Part 4] Using the Catalog Example with GlusterFS
 
== [https://github.com/tobegit3hub/seagull Seagull] ==
https://youtu.be/TuT5gb8oRw8
 
<pre>
docker run -d -p 127.0.0.1:10086:10086 -v /var/run/docker.sock:/var/run/docker.sock tobegit3hub/seagull
</pre>
 
The only issue is there is no username/password to protect other people to access the web GUI. The solution of binding to localhost to restrict the access does not work for remote administration.
 
That is, the tool is suitable for home use.
 
== [https://kitematic.com/ Kitematic] (Mac, Windows and Ubuntu) ==
Owned by Docker. Available for Mac OS X 10.8+ and Windows 7+ (64-bit) and Ubuntu. https://github.com/docker/kitematic/releases/
 
Run containers through a simple, yet powerful graphical user interface.
 
It can not connect to remote docker machines.


=== Connect to Docker daemon over ssh using docker-compose ===
A [https://www.r-bloggers.com/share-your-shiny-apps-with-docker-and-kitematic/ Share your Shiny Apps with Docker and Kitematic!]
[https://medium.com/@sujaypillai/dockertips-connect-to-docker-daemon-over-ssh-using-docker-compose-f4b189dd8951 #DockerTips: Connect to Docker daemon over ssh using docker-compose]


=== Dockerfile + docker-compose ===
== [https://github.com/shipyard/shipyard Shipyard] (retired) ==
[https://stackoverflow.com/a/29487120 Docker Compose vs. Dockerfile - which is better?]  
* [https://www.sumologic.com/blog/code/managing-containers-docker-shipyard/ Managing Containers with Docker Shipyard]
* Three alternatives:
** [http://rancher.com/ Rancher]
** [https://github.com/kevana/ui-for-docker Docker UI]
** [https://portainer.io/ Portainer]


The Compose file describes the container in its running state, leaving the details on how to build the container to Dockerfiles.
== VS Code ==
* [https://youtu.be/i7ABlHngi1Q Docker For Beginners: From Docker Desktop to Deployment]
* [https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers Visual Studio Code Remote - Containers]
* [https://www.docker.com/blog/how-to-develop-inside-a-container-using-visual-studio-code-remote-containers/ How to Develop Inside a Container Using Visual Studio Code Remote Containers]
* [https://www.cloudsavvyit.com/12837/how-to-edit-code-in-docker-containers-with-visual-studio-code/ How to Edit Code in Docker Containers With Visual Studio Code]


=== How to deploy on remote Docker hosts with docker-compose ===
= Applications =
[https://www.docker.com/blog/how-to-deploy-on-remote-docker-hosts-with-docker-compose/ How to deploy on remote Docker hosts with docker-compose]
[[Docker_Applications|Docker Applications]]
 
== Package CLI Applications ==
[https://www.cloudsavvyit.com/15713/how-to-use-docker-to-package-cli-applications/ How to Use Docker to Package CLI Applications]
 
== Stack ==
* https://www.composerize.com/
* [https://youtu.be/-ttZjGBkLL8 Export Docker Container Settings as Docker Compose Stack], [https://github.com/Red5d/docker-autocompose docker-autocompose] (only x86)
 
== Docker app ==
Docker App is an experimental Docker feature which lets you build and publish application stacks consisting of multiple containers. It aims to let you share '''Docker Compose''' stacks with the same ease of use as regular Docker containers.
 
[https://www.cloudsavvyit.com/10673/how-to-use-docker-app-to-containerise-an-entire-application-stack/ How to Use 'Docker App' to Containerise an Entire Application Stack]
 
== Docker Swarm ==
* https://www.linux.com/learn/how-use-docker-machine-create-swarm-cluster
* [https://www.howtoforge.com/tutorial/ubuntu-docker-swarm-cluster/ How Setup and Configure Docker Swarm Cluster on Ubuntu]
* [https://www.cloudsavvyit.com/13049/what-is-docker-swarm-mode-and-when-should-you-use-it/ What is Docker Swarm Mode and When Should You Use It?]


== Security ==
== CasaOS ==
* [https://cloudberry.engineering/article/dockerfile-security-best-practices/ Docker Security Best Practices from the Dockerfile]
* https://casaos.io/
* [https://www.cloudsavvyit.com/12631/how-to-secure-sensitive-data-with-docker-compose-secrets/ How to Secure Sensitive Data With Docker Compose Secrets]
* [https://youtu.be/FwJByjTdKks Revisiting CasaOS After A Few Months] 2022-6-14
 
== [https://mobyproject.org/ Moby Project] ==
[https://www.infoworld.com/article/3193904/containers/what-is-dockers-moby-project.html What is Docker's Moby Project?]
 
== Windows container ==
[https://stackoverflow.com/questions/45380972/how-can-i-run-a-docker-windows-container-on-osx How can I run a docker windows container on osx?]
 
== When Not to Use Docker ==
[https://www.cloudsavvyit.com/15446/when-not-to-use-docker-cases-where-containers-dont-help/ When Not to Use Docker: Cases Where Containers Don’t Help]
 
= Applications =
[[Docker_Applications|Docker Applications]]


= Orchestrator =
= Orchestrator =
Line 2,747: Line 2,813:
* http://training.play-with-docker.com/, [https://training.play-with-docker.com/alacart/ A full list of labs]
* http://training.play-with-docker.com/, [https://training.play-with-docker.com/alacart/ A full list of labs]
* https://blog.docker.com/2017/07/best-way-learn-docker-free-play-docker-pwd/
* https://blog.docker.com/2017/07/best-way-learn-docker-free-play-docker-pwd/
* One session is 4 hours. Each session can have multiple instance. Each instance will be allocated 4GB mem. Each docker image is stored in memory.
* '''df -h''' shows there is only 4.7G space for /var/lib/docker directory
* It is based on Alpine Linux. To install htop, do '''apk add htop'''. But '''htop''' command shows the resource from the host, not from the user's account.
* '''ctrl + insert''' to copy and '''shift + insert''' to paste
* Some applications I've tested.
** webtop (OK)
** r-base:3.6.3, r-base:4.1.0, r-base:4.1.1 (OK)
** r-base:4.1.2, r-base:4.2.0 (ERROR: R_HOME ('/usr/lib/R') not found). Maybe the docker version there is too old.


== Alternatives ==
== Alternatives ==

Revision as of 09:32, 6 September 2022

Official web page http://docker.io.

Docker is both a client and a server: the server is a daemon that runs on Linux. The normal approach was that you used docker on the same server the daemon was running on - however it was possible to connect the docker client to a remote docker daemon.

Installation

Which OS to install?

Containers vs virtual machines

KubeVirt

OS containers vs application containers

Differences:

  • OS containers: LXC, OpenVZ, Linux VServer, BSD Jails and Solaris zones. The container acts as VPS.
  • App containers: Docker, Rocket. The container acts as an application.

Current release version

Ubuntu x86 and Mint

Docker Desktop

Without sudo, Post-installation

To use docker without sudo, follow the instruction on the official guide.

# Add the docker group if it doesn't already exist.
# sudo groupadd docker

# Add your user to the docker group.
sudo usermod -aG docker $USER

# Log out and log in

Upgrade Docker Desktop

It seems it does not affect running containers (e.g. RStudio on Mac).

Is it fine to upgrade Docker-ce while a container is running?

Doesn't matter. Your system will stop the container if you update docker.

Is there a way to hibernate a docker container

Live restore

Rate limits for GitHub Apps

Rate limits for GitHub Apps

When I tried several times of docker build, I finally got a message

Downloading GitHub repo XXX/XXXXX@HEAD
Error: Failed to install 'unknown package' from GitHub:
  HTTP error 403.
  API rate limit exceeded for XXX.XX.XXX.X. (But here's the good news: Authenticated requests get a higher rate limit. Check out the documentation for more details.)

  Rate limit remaining: 0/60
  Rate limit reset at: 2021-04-12 20:32:28 UTC

  To increase your GitHub API rate limit
  - Use `usethis::browse_github_pat()` to create a Personal Access Token.
  - Use `usethis::edit_r_environ()` and add the token as `GITHUB_PAT`.
Execution halted

CentOS

https://docs.docker.com/engine/installation/linux/docker-ce/centos/

Boot2Docker

For Windows and OS operation systems, we have to use Boot2Docker. Boot2Docker is a local virtual machine with its own network interface and IP address. To find the Boot2Docker IP address you can check the value of the DOCKER_HOST environment variable. You're be prompted to set this variable when you start or install Boot2Docker the first time. You can find the IP address by running boot2docker ip command.

Note that since Windows and OS X don't share a file system as Linux, the command 'docker run' with '-v' flag to mount a local directory into a Docker container will not work with Boot2Docker release prior to 1.3. The support for volumes is now available for OS X but is not yet present for Windows with the release of Boot2Docker 1.3.

Windows

Note many of the information here have not been updated.

Docker can be run on Windows 10 Pro as a native application; see

The information below is based on running Docker on Windows 7.1 and 8. Your processor needs to support hardware virtualization.

  • Windows Installer includes msys-git, Virtualbox, Boot2Docker-cli management tool and Boot2Docker ISO.
  • Installation instruction for Windows OS. It will install Boot2Docker management tool with the boot2docker iso (based on Tiny Core Linux), Virtualbox and MYSYS-git UNIX tools.
  • Docker needs Admin right to be installed. However, Virtualbox can be installed by user's account.
  • If the installer detects a version of VirtualBox installed, the VirtualBox checkbox will not be checked by default (Windows OS). The VirtualBox cannot be used anymore after updating my VB from 4.3.18 to 4.3.20. The error may be related to Windows update according to Virtualbox forum.
Error in supR3HardenedWinReSpawn
  • Note that boot2docker cannot be installed/run inside a Windows guest machine. See this post and my Virtualbox wiki here. If we try to launch boot2docker-vm from Virtualbox, we will see a message "This kernel requires an x86-64 CPU, but only detected an i686 CPU."
  • After I switch back to an old version of virtualbox, every thing works again. I can even install Docker successfully.
    • Boot2Docker Start icon cannot be run directly because Notepad++ will automatically open it. A possible solution is to go to control panel and change default program for .sh file from Notepad++ to C:\Program Files (x86)\Git\bin\bash.exe.
    • The above step does not work well since a terminal appears and disappears quickly.
    • A working approach is to open Git Bash from Start menu. And run /c/Program Files/Boot2DockerforWindows/start.sh (or boot2docker start or boot2docer init)
    • A new VM called 'boot2docker-vm' will be created (we can open VirtualBox Manager to check). But I got an error error in run: Failed to start machine "boot2docker-vm" (run again with -v for details). The VM has an error on Network>Adapter2>VirtualBox Host-Only Ethernet Adapter #2. So I open the setting of <boot2docker-vm>, go to Network > Adapter 2 and change the dropdown list of Name from VirtualBox Host-Only Ethernet Adapter #2 to VirtualBox Host-Only Ethernet Adapter.
    • Now it works either I directly click boot2docker-vm VM from VB Manager or use the command start.sh from Git Bash.

Boot2docker-vm.png

$ # boot2docker is in the PATH variable, so there is not need to cd to the folder.
$ boot2docker start
initializing...
Virtual machine boot2docker-vm already exists

starting...
Waiting for VM and Docker daemon to start...
........o
Started.
Writing c:\Users\brb\.boot2docker\certs\boot2docker-vm\ca.pem
Writing c:\Users\brb\.boot2docker\certs\boot2docker-vm\cert.pem
Writing c:\Users\brb\.boot2docker\certs\boot2docker-vm\key.pem
Docker client does not run on Windows for now. Please use
    "c:\Program files\Boot2Docker for Windows\boot2docker.exe" ssh
to SSH into the VM instead.


192.168.56.101
connecting...
                        ##        .
                  ## ## ##       ==
               ## ## ## ##      ===
           /""""""""""""""""\___/ ===
      ~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ /  ===- ~~~
           \______ o          __/
             \    \        __/
              \____\______/
 _                 _   ____     _            _
| |__   ___   ___ | |_|___ \ __| | ___   ___| | _____ _ __
| '_ \ / _ \ / _ \| __| __) / _` |/ _ \ / __| |/ / _ \ '__|
| |_) | (_) | (_) | |_ / __/ (_| | (_) | (__|   <  __/ |
|_.__/ \___/ \___/ \__|_____\__,_|\___/ \___|_|\_\___|_|
Boot2Docker version 1.4.1, build master : 86f7ec8 - Tue Dec 16 23:11:29 UTC 2014

Docker version 1.4.1, build 5bc2ff8
docker@boot2docker:~$ docker
Usage: docker [OPTIONS] COMMAND [arg...]

A self-sufficient runtime for linux containers.

Options:
  --api-enable-cors=false                      Enable CORS headers in the remote
 API
  -b, --bridge=""                              Attach containers to a pre-existi
ng network bridge
...
Run 'docker COMMAND --help' for more information on a command.
docker@boot2docker:~$ docker run hello-world
Unable to find image 'hello-world:latest' locally
hello-world:latest: The image you are pulling has been verified
511136ea3c5a: Pull complete
31cbccb51277: Pull complete
e45a5af57b00: Pull complete
Status: Downloaded newer image for hello-world:latest
Hello from Docker.
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (Assuming it was not already locally available.)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

For more examples and ideas, visit:
 http://docs.docker.com/userguide/

docker@boot2docker:~$ ls
boot2docker, please format-me
docker@boot2docker:~$ pwd
/home/docker
docker@boot2docker:~$ ls /
bin/     dev/     home/    lib/     mnt/     proc/    run/     sys/     usr/
c/       etc/     init     linuxrc  opt/     root/    sbin/    tmp      var/

docker@boot2docker:~$ docker run hello-world
Hello from Docker.
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (Assuming it was not already locally available.)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

For more examples and ideas, visit:
 http://docs.docker.com/userguide/
docker@boot2docker:~$
docker@boot2docker:~$
docker@boot2docker:~$
docker@boot2docker:~$ docker run -it ubuntu bash
Unable to find image 'ubuntu:latest' locally
ubuntu:latest: The image you are pulling has been verified
53f858aaaf03: Pull complete
837339b91538: Pull complete
615c102e2290: Pull complete
b39b81afc8ca: Pull complete
511136ea3c5a: Already exists
Status: Downloaded newer image for ubuntu:latest


root@ea7e3289a01a:/# pwd
/
root@ea7e3289a01a:/# df -h
Filesystem      Size  Used Avail Use% Mounted on
rootfs           19G  269M   17G   2% /
none             19G  269M   17G   2% /
tmpfs          1005M     0 1005M   0% /dev
shm              64M     0   64M   0% /dev/shm
/dev/sda1        19G  269M   17G   2% /etc/hosts
tmpfs          1005M     0 1005M   0% /proc/kcore
root@ea7e3289a01a:/# ls
bin   dev  home  lib64  mnt  proc  run   srv  tmp  var
boot  etc  lib   media  opt  root  sbin  sys  usr
root@ea7e3289a01a:/# exit
exit


docker@boot2docker:~$ pwd
/home/docker
docker@boot2docker:~$ ls
boot2docker, please format-me
docker@boot2docker:~$ exit
[Press any key to exit]

brb@NCI-01825357 /c/Program files/Boot2Docker for Windows
$ boot2docker down

brb@NCI-01825357 /c/Program files/Boot2Docker for Windows
$
$ boot2docker --help
Usage: c:\Program files\Boot2Docker for Windows\boot2docker.exe [<options>] <command> [<args>]

Boot2Docker management utility.

Commands:
   init                Create a new Boot2Docker VM.
   up|start|boot       Start VM from any states.
   ssh [ssh-command]   Login to VM via SSH.
   save|suspend        Suspend VM and save state to disk.
   down|stop|halt      Gracefully shutdown the VM.
   restart             Gracefully reboot the VM.
   poweroff            Forcefully power off the VM (may corrupt disk image).
   reset               Forcefully power cycle the VM (may corrupt disk image).
   delete|destroy      Delete Boot2Docker VM and its disk image.
   config|cfg          Show selected profile file settings.
   info                Display detailed information of VM.
   ip                  Display the IP address of the VM's Host-only network.
   shellinit           Display the shell commands to set up the Docker client.
   status              Display current state of VM.
   download            Download Boot2Docker ISO image.
   upgrade             Upgrade the Boot2Docker ISO image (restart if running).
   version             Display version information.

Options:
      --basevmdk="": Path to VMDK to use as base for persistent partition
      --clobber=false: overwrite Docker client binary on boot2docker upgrade
      --dhcp=true: enable VirtualBox host-only network DHCP.
      --dhcpip=192.168.59.99: VirtualBox host-only network DHCP server address.
....
  -v, --verbose=false: display verbose command invocations.
      --vm="boot2docker-vm": virtual machine name.
      --waittime=300: Time in milliseconds to wait between port knocking retries during 'start'
error in run: config error: pflag: help requested

brb@NCI-01825357 /c/Program files/Boot2Docker for Windows

The big picture


                           start.sh                      docker run -it ubuntu bash
Git Bash Git Bash         ---------->  boot2docker-vm       ------------->   ubuntu
                                   docker@boot2docker:
   <-------               <----------                       <------------- 
   boot2docker down           exit                                 exit
   (shutdown boot2docker) (boot2docker-vm is still on)
    |
    |
    |  boot2docker up (start boot2docker)
    |
    |  boot2docker ssh (log into docker acct)
    |
    v
   boot2docker-vm
   docker@boot2docker

Increase boot2docker vmdk space

https://docs.docker.com/articles/b2d_volume_resize/

Install utilities in Boot2docker VM

http://blog.tutum.co/2014/11/05/how-to-use-docker-on-windows/

For example, to install cifs-utils,

wget http://distro.ibiblio.org/tinycorelinux/5.x/x86/tcz/cifs-utils.tcz
tce-load -i cifs-utils.tcz

WSL2

Mac

  • https://docs.docker.com/desktop/mac/
  • Alternatives to Docker Desktop for Mac? Rancher is recommended. 2022-06-08
  • Vagrant method. If you have Mac, you don't have to use boot2docker (iso & its management tool). You can use other Linux which comes with docker pre-installed. See this post.

ARM architeture from hub.docker.com

curl -sSL https://get.docker.com | sh
  • UDOO Quad running Armbian 20.04
    • The instruction on official Docker website does not work
    • The curl command method above does not work
    • sudo apt-get install -y docker.io works (docker -v shows it is 19.03.8). After that, run sudo usermod -aG docker $USER and log out/in.
  • See Odroid magazine 2015 January and 2015 February. Note that the current versions of Docker and Docker Hub are not aware of the architecture for which the image has been built. All standard images are intended for the x86 architecture, and the autobuild feature offered by the Docker registry is only available for x86.
  • NVIDIA Jetson Nano Developer Kit - Introduction, Redis running inside Docker container on NVIDIA Jetson Nano
sudo apt install curl
curl -sSL https://get.docker.com/ | sh

docker-compose

Some examples*

Not I use the arm64 image on my Pi3b+.

Images from https://www.linuxserver.io/. Some indices include number of pulls and stars.

List of tz database time zones

Portainer. The port number is 9000. Note the stack will be deployed using the equivalent of docker-compose. Only Compose file format version 2 is supported at the moment.

Samba. Tested on iOS, Ubuntu & Windows 10.

mkdir -p /mnt/usb/share/{data,backups}
mkdir /mnt/usb/share/data/{alice,bob,documents}
touch /mnt/usb/share/backups/backupsfile
touch /mnt/usb/share/data/bob/bobfile
touch /mnt/usb/share/data/documents/documentfile

docker run -d -p 445:445 \
  -v /mnt/usb/share/data:/share/data \
  -v /mnt/usb/share/backups:/share/backups \
  --name rpi-samba trnape/rpi-samba \
  -u "alice:abc123" \
  -u "bob:secret" \
  -u "guest:guest" \
  -s "Backup directory:/share/backups:rw:alice,bob" \
  -s "Bob (private):/share/data/bob:rw:bob" \
  -s "Documents (readonly):/share/data/documents:ro:guest,alice,bob" 

On Windows, 1) right click on 'This PC' and choose 'Add a network location'. 2) type \\192.168.1.249\ and the dropdown list will populate all available folders. 3) choose the one (e.g. Bob) and then enter the credential. Done. On Ubuntu, just type smb://192.168.1.249/. It will then populate the available folders.

Nginx

mkdir -p /mnt/usb/docker-nginx/html
echo "hello world" >> /mnt/usb/docker-nginx/html/index.html
nano /mnt/usb/docker-nginx/html/sharefile
docker run --name rpi-nginx -p 8086:80 \
  --restart always \
  -v /mnt/usb/docker-nginx/html:/usr/share/nginx/html \
  -d nginx:stable-alpine

# Or a stack file
version: '2'
services:
    nginx:
        container_name: rpi-nginx
        ports:
            - '8086:80'
        restart: always
        volumes:
            - '/mnt/usb/docker-nginx/html:/usr/share/nginx/html'
        image: nginx:stable-alpine

Note consider to use a samba share folder (see above) as a nginx document root.

cp /mnt/usb/docker-nginx/html/* /mnt/usb/share/data/bob/
rm -rf /mnt/usb/docker-nginx/html
ln -s /mnt/usb/share/data/bob/ /mnt/usb/docker-nginx/html

Rpi-monitor. I need to change /dev/vcsm to /dev/vcsm-cma. But the temperature part is not working. I am using 64-bit Raspberry Pi OS and it does not show attached USB disks. The port number is 8888.

code-server

---
version: "2.1"
services:
  code-server:
    image: ghcr.io/linuxserver/code-server
    container_name: code-server
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=America/New_York
      - PASSWORD=password #optional
      - SUDO_PASSWORD=password #optional
    volumes:
      - /mnt/usb/code-server:/config
    ports:
      - 8443:8443
    restart: unless-stopped

mstream Music streaming. Works great.

emby does not work on arm64. It works on x86 though. Even I copy a mp4 file to movies directory the movie does not show up:(

version: '2.1'
services:
    embyserver:
        container_name: emby
        network_mode: bridge
        restart: always
        environment:
            - VERSION=latest
            - UID=1000
            - GID=1000
            - TZ=America/Denver
        volumes:
            - /media/crucial/emby/config:/config
            - /media/crucial/emby/tv:/mnt/tv
            - /media/crucial/emby/movies:/mnt/movies
        ports:
            - 8096:8096            
        image: 'emby/embyserver:latest'

jellyfin Jellyfin is descended from Emby's 3.5.2 release and ported to the .NET Core framework to enable full cross-platform support. How to Install Jellyfin on Docker with Portainer

plex We can access the plex server via http://IP:32400/web. Note that in the first server setup, we need to add Library' by choosing the new library name (eg Other Videos) shown on plex & the data source (eg /data) so our own media can be found. After we added new media files we can rescan by clicking the vertical 3 dots icon and selecting scan library files. Pi3b+ is still a little weak since I can see all threads are busy when I played a mp4 file.

mkdir -p /mnt/usb/plex/{config,data}
cp FILENAme.mp4 /mnt/usb/plex/data
docker run \
  -d \
  --name plex \
  --net host \
  -p 32400:32400 \
  --restart always \
  --volume /mnt/usb/plex/config:/config \
  --volume /mnt/usb/plex/data:/data \
  greensheep/plex-server-docker-rpi:latest

WARNING: The requested image's platform (linux/arm) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested

Nextcloud.

sudo mkdir -p /srv/dev-disk-by-label-Files/Databases/NextCloud
sudo mkdir -p /srv/dev-disk-by-label-Files/Config/Nextcloud

After that, copy and paste the stack into portainer. Wait for a few minutes on RPi3. The port number is 8080. Now we can create the admin username/password such as nextcloud/nextcloud. Click the little triangle next to "Storage and Database". Change to MySQL. In the next part we enter nextcloud/nextcloud/nextcloud/db (note the "db" replaces localhost b/c we use "db" as the service name). Again, wait for a few minutes.

Heimdall (Dashboard for web apps). I keep the PUID (1000) and PGID (1000). The instruction says it is from the admin user account but I don't find admin account? Change the volume to /srv/dev-disk-by-label-Files/Config/Heimdall (use sudo mkdir to create the directory on terminal). Change the port to 83 & remove port 443. Define the endpoint from Portainer -> Endpoints -> local -> Public IP as raspberrypi.local (depending on your hostname). We need to wait a little bit. Now go to the container and find heimdall and click the port in order to open the website correctly (instead 0.0.0.0). I can add apps like nextcloud, portainer, pi-hole, other servers, etc. The Application Type entry has a good list of popular apps and it will pre-populate the button icon and the background color for our app.

taisun The default port is 3000

yacht. The default login is [email protected] and pass. The name shown on portainer is pedantic_hermann

docker volume create yacht
docker run -d -p 8001:8000 -v /var/run/docker.sock:/var/run/docker.sock -v yacht:/config selfhostedpro/yacht

CloudFlare DDNS - Update CloudFlare with Your Dynamic IP Address

WatchTower

bitwardenrs. Use the terminal to create a volume first. The port number is 8100. This is straightforward.

Duplicati for backup.

photoshow. It works. It has a slideshow button. PhotoShow only displays videos in WebM.

R. r-base provide arm64 image but not not 32-bit arm architecture.

# 64-bit OS
docker pull r-base
docker run -it --rm r-base   # enter R directly

rocker/rstudio DOES NOT work on arm64 even I can pull. WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested

I build a 32-bit armv7 image for r-base v4.0.2. This image works on either 32-bit or 64-bit arm OS (tested on 32-/64-bit Raspberry Pi and other 32-bit SBC devices).

docker pull arraytools/r402armv7
docker run -it --rm arraytools/r402armv7 R
docker pull r-base
# Using default tag: latest
# latest: Pulling from library/r-base
# no matching manifest for linux/arm/v7 in the manifest list entries

How and Why to Use A Remote Docker Host

Backup

Usage

Basics, docs, cheatsheet

Note that we need sudo is needed unless it is on a Mac OS.

If docker cannot find an image, it will try to pull it from its repository.

$ sudo docker run -it ubuntu /bin/bash
Unable to find image 'ubuntu' locally
Pulling repository ubuntu
04c5d3b7b065: Download complete 
511136ea3c5a: Download complete 
c7b7c6419568: Download complete 
70c8faa62a44: Download complete 
d735006ad9c1: Download complete 
root@ec83b3ac878d:/# 
purpose command
run a container docker container run -d -p 80:80 httpd
list running cotainer docker container ls
view logs of Docker container docker container logs cranky_cori
identify Docker container process? docker container top cranky_cori
stop Docker container? docker container stop cranky_cori
list stopped or not running Docker containers docker container ls -a
start Docker container docker container start c46f2e9e4690
remove Docker container docker container rm cranky_cori
list Docker images docker images
remove Docker image docker rmi iman/touch

Restart docker daemon

When I try the Chap5 > Continuous integration (Jenkins) of the Docker Book, I found I cannot stop/kill the container. See others' report here. The solution is to restart the docker daemon.

sudo service docker start

After that, I can stop and rm the container.

sudo docker stop jenkins
sudo docker rm jenkins
sudo docker ps -a

images vs containers

$ sudo docker images
REPOSITORY                     TAG                 IMAGE ID            CREATED              VIRTUAL SIZE
iman                           latest              6e0f5644b2fd        About a minute ago   460.4 MB
iman/touch                     latest              77b9ac5951c2        4 minutes ago        460.4 MB
<none>                         <none>              aaa75e64ddf0        5 weeks ago          188.3 MB
ouruser/sinatra                v2                  ea8c9f407a8d        5 weeks ago          447 MB
ubuntu                         14.04               ed5a78b7b42b        5 weeks ago          188.3 MB
ubuntu                         latest              ed5a78b7b42b        5 weeks ago          188.3 MB
eddelbuettel/docker-ubuntu-r   add-r-devel-san     3c19d078c5d9        3 months ago         460.4 MB
hello-world                    latest              ef872312fe1b        4 months ago         910 B
training/sinatra               latest              f0f4ab557f95        8 months ago         447 MB

$ sudo docker ps -a
CONTAINER ID IMAGE                                          COMMAND              CREATED        STATUS                   PORTS NAMES
8fbdbcdb5126 iman/touch:latest                              "/bin/bash"          2 minutes ago  Exited (0) 2 minutes ago       thirsty_engelbart   
dc9e82f2c00a eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          9 minutes ago  Exited (0) 3 minutes ago       kickass_bardeen     
532a90f36aa8 eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          18 hours ago   Exited (0) 18 hours ago        happy_lalande       
7634024ee0bf eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          18 hours ago   Exited (0) 18 hours ago        insane_mclean       
14034a9720cb eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          18 hours ago   Exited (0) 18 hours ago        naughty_lumiere     
ca90954628db eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          19 hours ago   Exited (130) 18 hours ago      sick_hawking        
8bbdcb7c339f eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          19 hours ago   Exited (0) 19 hours ago        modest_davinci      
e8e24f80f0dd aaa75e64ddf0                                   "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago       berserk_hodgkin     
d41959e0eb55 aaa75e64ddf0                                   "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago       jovial_curie        
b408c0e2805b aaa75e64ddf0                                   "/bin/sh -c 'apt-get 5 weeks ago    Exited (100) 5 weeks ago       lonely_tesla        
72a551e4b492 ouruser/sinatra:v2                             "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago         jolly_meitner       
75fd6cc4658b training/sinatra:latest                        "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago         evil_yalow          
cc8886f5a02e training/sinatra:latest                        "/bin/bash"          5 weeks ago    Exited (130) 5 weeks ago       elegant_curie       
0585e4f5fecd eddelbuettel/docker-ubuntu-r:add-r-devel-san   "/bin/bash"          5 weeks ago    Exited (0) 5 weeks ago         elated_euclid       
brb@brbweb4:~/Downloads$ 

When we want to delete a container, we use the container's CONTAINER ID or NAME (last column output from docker ps -a). But when we want to delete an image, we use the image's REPOSITORY or IMAGE ID (2nd column output from docker images)

$ sudo docker rm thirsty_engelbart  # iman/touch
$ sudo docker rm dc9e82f2c00a       # eddelbuettel/docker-ubuntu-r:add-r-devel-san
$ sudo docker ps -a   # check to see the container is gone now

$ sudo docker rmi 6e0f5644b2fd
$ sudo docker rmi iman/touch
$ sudo docker images  # check to see the images are gone now

Command line interface, CLI

https://docs.docker.com/engine/reference/commandline/cli/ Docker command line

$ docker

Usage:	docker COMMAND

A self-sufficient runtime for containers

Options:
      --config string      Location of client config files (default "/home/brb/.docker")
  -D, --debug              Enable debug mode
  -H, --host list          Daemon socket(s) to connect to
  -l, --log-level string   Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
      --tls                Use TLS; implied by --tlsverify
      --tlscacert string   Trust certs signed only by this CA (default "/home/brb/.docker/ca.pem")
      --tlscert string     Path to TLS certificate file (default "/home/brb/.docker/cert.pem")
      --tlskey string      Path to TLS key file (default "/home/brb/.docker/key.pem")
      --tlsverify          Use TLS and verify the remote
  -v, --version            Print version information and quit

Management Commands:
  config      Manage Docker configs
  container   Manage containers
  image       Manage images
  network     Manage networks
  node        Manage Swarm nodes
  plugin      Manage plugins
  secret      Manage Docker secrets
  service     Manage services
  swarm       Manage Swarm
  system      Manage Docker
  trust       Manage trust on Docker images
  volume      Manage volumes

Commands:
  attach      Attach local standard input, output, and error streams to a running container
  build       Build an image from a Dockerfile
  commit      Create a new image from a container's changes
  cp          Copy files/folders between a container and the local filesystem
  create      Create a new container
  diff        Inspect changes to files or directories on a container's filesystem
  events      Get real time events from the server
  exec        Run a command in a running container
  export      Export a container's filesystem as a tar archive
  history     Show the history of an image
  images      List images
  import      Import the contents from a tarball to create a filesystem image
  info        Display system-wide information
  inspect     Return low-level information on Docker objects
  kill        Kill one or more running containers
  load        Load an image from a tar archive or STDIN
  login       Log in to a Docker registry
  logout      Log out from a Docker registry
  logs        Fetch the logs of a container
  pause       Pause all processes within one or more containers
  port        List port mappings or a specific mapping for the container
  ps          List containers
  pull        Pull an image or a repository from a registry
  push        Push an image or a repository to a registry
  rename      Rename a container
  restart     Restart one or more containers
  rm          Remove one or more containers
  rmi         Remove one or more images
  run         Run a command in a new container
  save        Save one or more images to a tar archive (streamed to STDOUT by default)
  search      Search the Docker Hub for images
  start       Start one or more stopped containers
  stats       Display a live stream of container(s) resource usage statistics
  stop        Stop one or more running containers
  tag         Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
  top         Display the running processes of a container
  unpause     Unpause all processes within one or more containers
  update      Update configuration of one or more containers
  version     Show the Docker version information
  wait        Block until one or more containers stop, then print their exit codes

Run 'docker COMMAND --help' for more information on a command.

Version, system information

Docker version

$ docker version
Client:
 Version:           18.06.1-ce
 API version:       1.38
 Go version:        go1.10.3
 Git commit:        e68fc7a
 Built:             Tue Aug 21 17:24:51 2018
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          18.06.1-ce
  API version:      1.38 (minimum version 1.12)
  Go version:       go1.10.3
  Git commit:       e68fc7a
  Built:            Tue Aug 21 17:23:15 2018
  OS/Arch:          linux/amd64
  Experimental:     false

System information.

  • what mode the Docker engine is operating in (swarm mode or not)
  • what storage drive is used for the union filesystem
  • what version of the Linux kernel we have on our host
  • et al
$ docker system info
Containers: 2
 Running: 0
 Paused: 0
 Stopped: 2
Images: 10
Server Version: 18.06.1-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 468a545b9edcd5932818eb9de8e72413e616e86e
runc version: 69663f0bd4b60df09991c08812a60108003fa340
init version: fec3683
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 4.15.0-33-generic
Operating System: Ubuntu 18.04.1 LTS
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 7.674GiB
Name: t420s
ID: VLWB:6BN3:U7KB:L4T4:GQIB:54F3:YZKJ:PAIR:HEUM:UQIC:XLZU:3IFJ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

WARNING: No swap limit support

List resource consumption

$ docker system df
TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              10                  2                   2.58GB              1.519GB (58%)
Containers          2                   0                   304B                304B (100%)
Local Volumes       2                   0                   314.7MB             314.7MB (100%)
Build Cache         0                   0                   0B                  0B

$ docker system df -v  # more detailed information
# We can use the information to clean up our system

A brief intro to docker virtualization

docker search --help
docker search redis
docker search -s 100 redis
docker pull --help
docker pull ubuntu # download all versions of ubuntu
docker images    # available local container images
docker pull centos:latest
docker run --help
cat /etc/issue   # look at the current distr name before running docker
docker run -it centos:latest /bin/bash
                 # create a container & execute as a sudo

cat /etc/redhat-release
yum
cd /home
touch temp.txt
ls
exit

docker ps   # current running processes
docker ps -a # show all processes including closed
docker restart c85850ed0e13
docker ps   # container c85850ed0e13 is running
docker attach c85850ed0e13 # log into the system

ls /home
exit

docker ps -a
docker rm c85850ed0e13 # delete the container

Note: Following the discussion, using attach can only launch one instance of shell. If we use exec, we can launch multiple instances.

sudo docker exec -i -t c85850ed0e13 bash #by ID
or
$ sudo docker exec -i -t loving_heisenberg bash #by Name

docker pull

https://docs.docker.com/engine/reference/commandline/pull/

$ docker pull ubuntu:zesty
$ docker run -ti --rm ubuntu:zesty /bin/bash 
# lsb_release -a         
bash: lsb_release: command not found
# cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=17.04
DISTRIB_CODENAME=zesty
DISTRIB_DESCRIPTION="Ubuntu 17.04"
NAME="Ubuntu"
VERSION="17.04 (Zesty Zapus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 17.04"
VERSION_ID="17.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=zesty
UBUNTU_CODENAME=zesty

Update/upgrade images

<none>:<none> images

Exit/detach from a container without stopping it

$ docker container run -it ubuntu:latest /bin/bash
# Ctrl+p, Ctrl+q to exit the container without terminating it
$ docker ps -a # showing the container 70c5aceb5512 is running in the background

# You can reattach your terminal to it with the "docker container exec" command
$ docker container exec -it 70c5aceb5512 bash

How to start a stopped Docker container with a different command

How to start a stopped Docker container with a different command?

Clean shutdown DOCKER containers before reboot

Dockerizing Applications/Detached mode

$ sudo docker run -d --name insane_babbage ubuntu:14.04 /bin/sh -c "while true; do echo hello world; sleep 1; done"
$ sudo docker ps -l
$ sudo docker logs insane_babbage
$ sudo docker stop insane_babbage
$ sudo docker ps

The -d flag tells Docker to run the container and put it in the background, to daemonize it.

According to https://docs.docker.com/engine/reference/run/#detached-vs-foreground, containers started in detached mode exit when the root process used to run the container exits, unless you also specify the --rm option. If you use -d with --rm, the container is removed when it is stopped, exits or when the daemon exits, whichever happens first.

Automatically restart after reboot

https://stackoverflow.com/questions/18786054/how-to-auto-restart-a-docker-container-after-a-reboot-in-coreos

Add a --restart=always parameter. It will always restart a stopped container unless it has been explicitly stopped, such as via a "docker container stop" command. See the following

$ docker run -d --restart always myCustomeDocker

$ docker container run --name neverdie -it --restart always ubuntu /bin/bash
# exit
$ docker ps -a  # the container is still ther
$ docker stop neverdie
$ docker ps -a

Working with Containers

$ sudo docker run -i -t ubuntu /bin/bash
$ sudo docker version
$ sudo docker
$ sudo docker attach --help

Environment variables

Alpine image

apk add htop

Running a Web Application

$ sudo docker run -d -P training/webapp python app.py

Alpine linux is 6MB. It is a good OS to run a web application. See the demo here.

Viewing our Web Application Container

$ sudo docker ps -l
$ sudo docker run -d -p 5000:5000 training/webapp python app.py

Check container status (docker status) - CPU, Memory usage

Container networking

Host network

If you use the host network driver for a container, that container’s network stack is not isolated from the Docker host. For instance, if you run a container which binds to port 80 and you use host networking, the container’s application will be available on port 80 on the host’s IP address.

ping, ifconfig and ip commands not found in Ubuntu container

apt update
apt install iputils-ping  # ping 
apt install net-tools     # ifconfig
apt install iproute2      # ip

Network Port Shortcut

$ sudo docker port nostalgic_morse 5000

Access Ports on the Host from a Docker Container

How to Access Ports on the Host from a Docker Container

Multiple NICs

containers in docker to use public ip addresses directly

Viewing the Web Application's Logs

$ sudo docker logs -f nostalgic_morse

Clear Logs of Running Docker Containers

How to Clear Logs of Running Docker Containers

Looking at our Web Application Container's processes

$ sudo docker top nostalgic_morse

Inspecting our Web Application Container

$ sudo docker inspect nostalgic_morse

Obtain the container's IP address, log into a running server

PS. Portainer web interface can show the IP addresses.

$ docker inspect <container id> | grep "IPAddress"

We don't need the IP address if we just want to log into a running server,

$ docker exec -it <contianer id> bash

How to Secure Docker’s TCP Socket

How to Secure Docker’s TCP Socket with TLS

docker attach

Suppose I run docker run -it --user rstudio bioconductor/bioconductor_docker:devel R and I use q() to quit the container. The container is still there. To re-enter the R in the container, I use

docker start XXXXXXXX    # restart it in the background
docker attach XXXXXXXX   # reattach the terminal & stdin

If we want the latest created container, then we use

docker start `docker ps -q -l` && docker attach `docker ps -q -l`

docker exec: SSH into a running container

Run a command in a running container

  • Usage:
    docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
  • Examples:
    $ docker exec -d ubuntu_bash touch /tmp/execWorks # do st in the background
    
    $ docker exec -it ubuntu_bash bash
    
    $ docker exec -it -e VAR=1 ubuntu_bash bash # set an environment variable
    
    $ docker exec -it ubuntu_bash pwd
    $ docker exec -it -w /root ubuntu_bash pwd # change the working directory
  • How to Run a Command on a Running Docker Container

docker cp

Copy files/folders between a container and the local filesystem.

Restart an exited Container

$ docker start nostalgic_morse
OR
$ docker restart nostalgic_morse

For an interactive container, use docker start -ai CONTAINER which is equal to run "docker start CONTAINER" and "docker attach CONTAINER".

Rename a container

docker container rename

docker container rename CONTAINER NEW_NAME

Inspect container images and their metadata

Know the container size

docker ps -s

Meaning of two sizes

  • The "size" information shows the amount of data (on disk) that is used for the writable layer of each container
  • The "virtual size" is the amount of disk-space used for the read-only image data used by the container.

Removing our Web Application Container

$ sudo docker stop nostalgic_morse
$ sudo docker rm nostalgic_morse

Note: Always remember that deleting a container is final!

Dockerize an SSH service

https://docs.docker.com/engine/examples/running_ssh_service/#environment-variables

Remove old docker containers

This post on stackoverflow.com.

$ sudo docker ps -a | grep 'weeks ago' | awk '{print $1}' | xargs --no-run-if-empty sudo docker rm

Similarly to remove all exited containers

$ sudo docker ps -a | grep Exit | awk '{print $1}' | xargs sudo docker rm

To kill/stop (not delete) all running containers

$ sudo docker kill $(sudo docker ps -q)

To delete all stopped containers

$ sudo docker rm $(sudo docker ps -a -q)
OR
$ sudo docker rm `sudo docker ps -a -q`

It is also helpful to create bash aliases for these commands by editing ~/.bash_aliases file.

docker create vs docker run

https://stackoverflow.com/questions/37744961/docker-run-vs-create

docker create is similar to docker run -d except the container is never started.

Retrieve docker run command

https://stackoverflow.com/a/32774347. See the github page of runlike. So it is better to put the docker run in a stack. Then for example the Portainer has an Editor tab to show the compose file.

docker run --rm -v /var/run/docker.sock:/var/run/docker.sock \
    assaflavie/runlike -p CONTAINER_NAME

The -p option splits the output into pretty lines.

docker run -it and -d together

How to Modify the Configuration of Running Docker Containers

How to Modify the Configuration of Running Docker Containers

Volume

Examples of host's volume locations

/home/$USER/docker/$PROJECT/$SUB-DIRECTORY

Two ways to achieve persistent data

Inspect the 'Mountpoint' of a volume

$ docker volume create crv
$ docker volume ls

$ docker run -d \
     --name mycloud \
     -p 81:80 \
     -v apps:/var/www/html/custom_apps \
     nextcloud

# docker inspect is not quite useful. It does not show how the volume was created
# But we can examine (ls, du, ...) the directory contents
$ docker inspect apps   
[
    {
        "CreatedAt": "2018-10-23T09:41:52-04:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/apps/_data",
        "Name": "apps",
        "Options": null,
        "Scope": "local"
    }
]

Remove an an unnamed volume

If you created an unnamed volume, it can be deleted at the same time as the container with the -v flag. Note that this only works with unnamed volumes.

docker rm -v container_name

If the volume is named, it stays present. To remove a named volume, use docker volume rm volume_name .

Start a container with a volume

--mount -v
docker run -d \

--name devtest \
--mount source=myvol2,target=/app \
nginx:latest

docker run -d \

--name devtest \
-v myvol2:/app \
nginx:latext

Note

  • target in "--mount" can be replaced by destination or dst.
  • To use a read-only volume, add the ,readonly option in "--mount" or the :ro option in "-v".
  • We cannot use "~/" to represent a local directory under HOME. We have to specify a full path in docker run.

A simple example

From the book "Learn Docerk -Fundamentals of Docker 18.x". Chap 5. Data Volumes and System Management > Creating and mounting data volumes.

# Create a volume
docker volume create my-data
docker volume inspect my-data
# The host folder can be found in the output under 'Mountpoint'
# In my case,
#        "Mountpoint": "/var/lib/docker/volumes/my-data/_data",

# Mount a volume into a container
docker run --name test -it -v my-data:/data alpine /bin/sh
# cd /data
# echo 'some data' > data.txt
# echo 'more data' > data2.txt
# exit
docker inspect my-data
sudo ls /var/lib/docker/volumes/my-data/_data
# We can even try to output the content of say, the second file:
sudo cat /var/lib/docker/volumes/my-data/_data/data2.txt
# We can create a new file in this folder from the host and then use the volume with another container
echo "the file is created on host" > sudo tee /var/lib/docker/volumes/my-data/_data/host-data
# Let's delete the test container and run another one
docker rm test

# This time we are mounting our volume to a different container folder
docker run --name test2 -it -v my-data:/app/data centos:7 /bin/bash
# We are able to see three files:
# ls /app/data

# Remove volumes
docker volume rm my-data # Or 
docker volume rm $(docker volume ls -q)

# Remove all running containers to clean up the system,
docker rm -f $(docker ls -aq)

Sharing data between containers

How to Share Data Between Docker Containers

docker run -it --name writer -v shared-data:/data alpine /bin/sh
# create a file inside it
# echo 'my sample file' > /data/sample.txt
# exit
docker run -it --name reader -v shared-data:/app/data:ro ubuntu:17.04 /bin/bash
# ls -l /app/data

Using host volumes

Use volumes that mount a specific host folder

  • It may be possible for the "docker volume" command to mount a local directory to a volume. See examples in the "docker volume create" documentation.
  • Specifying a directory name instead of giving a volume name in the "docker run" 's -v option
  • Since we are specifying a directory name instead of letting docker to create a new volume, "docker volume ls" will not getting a new volume
docker run -it --name test -v $(pwd)/src:/app/src alpine /bin/sh

# Make a sample to demonstrate how that works
mkdir ~/my-web; cd ~/my-web
echo "<h1>My website</h1>" > index.html

# Create 'Dockerfile'
echo -e 'FROM nginx:alpine
COPY . /usr/share/nginx/html' > Dockerfile

docker image build -t my-website:1.0 .
docker run -d -p 8080:80 --name my-site my-website:1.0

# Open http://localhost:8080. It looks good
# Now modify index.html and refresh the website. It does not refresh
# Let's stop and rm the container and rebuild using a volume
docker rm -f my-site
docker run -d -v $(pwd):/usr/share/nginx/html \
   -p 8080:80 --name my-site my-website:1.0
# Now any changes on index.html will refresh on the website

Define volumes in images

A few samples of volume definition

VOLUME /app/data
VOLUME /app/data, /app/profiles, /app/config
VOLUME {"/app/data", "/app/profiles", "/app/config"]

The first line defines a single volume to be mounted at /app/data.

We can use the docker image inspect command to get information about the volumes defined in the Dockerfile.

docker image pull mongo:3.7
docker image inspect --format='{{json .ContainerConfig.Volumes}}' \
       mongo:3.7 | jq
# {
#   "/data/configdb": {},
#   "/data/db": {}
# }

# now run an instance of MongoDB and inspect the volume information
docker run --name my-mongo -d mongo:3.7
docker inspect --format '{{json .Mounts}}' my-mongo | jq
# [
#  {
#    "Type": "volume",
#    "Name": "535e0138b9a32e89f71380e9e73bb0de64ce0d1cad78fcda0ec1d49e11d76d7a",
#    "Source": "/var/lib/docker/volumes/535e0138b9a32e89f71380e9e73bb0de64ce0d1.../_data",
#    "Destination": "/data/configdb",
#    "Driver": "local",
#    "Mode": "",
#    "RW": true,
#    "Propagation": ""
#  },
#  {
#    "Type": "volume",
# SKIP

Differences between VOLUME and '-v|--volume'

https://stackoverflow.com/a/25312719

Container Memory Limits, Setting Available CPUs, Allocating memory and CPU

docker run \
    -rm \ ## Automatically remove the container when it exits
    --memory=6g \ ## memory limit
    --cpus=1.5 \ ## number of CPUs
    -v /shared/data-store:/home/rstudio/data \
    -v /shared/library-store:/usr/local/lib/R/host-site-library \
    -e PASSWORD=bioc \
    -p 8787:8787 \
         bioconductor/bioconductor_full:devel

Work with container images

List images by size or name

# by size
docker images --format "{{.ID}}\t{{.Size}}\t{{.Repository}}" | sort -k 2 -h

# by name
docker images --format "{{.ID}}\t{{.Size}}\t{{.Repository}}" | sort -k 3 

List specific columns

docker images --format 'table {{.Repository}}\t{{.Tag}}\t{{.Size}}'

Create an image interactively using commit - Example 1

The example is from the book 'Learn Docker - Fundamentals of Docker 18.x'.

docker container run -it --name sample alpine /bin/sh
# apk update && apk add iputils
# ping 127.0.0.1
# exit
docker container ls -a | grep sample
docker container diff sample

We can now use the docker container commit command to persist our modifications and create a new image from them

docker container commit sample my-alpine
docker images ls

If we want to see how our custom image has been built, we can use the history command as follows:

docker image history my-alpine
# IMAGE               CREATED              CREATED BY                                      SIZE    COMMENT
# 0f105057899b        About a minute ago   /bin/sh                                         1.55MB              
# 196d12cf6ab1        4 weeks ago          /bin/sh -c #(nop)  CMD ["/bin/sh"]              0B                  
# <missing>           4 weeks ago          /bin/sh -c #(nop) ADD file:25c10b1d1b41d46a1…   4.41MB

The first layer in the preceding list is the one we just created by adding the iputils package.

Create an image interactively using commit - Example 2

Note that it is better/necessary to put the Dockerfile in an empty directory to avoid the problem of taking a long time to build the image (sending build context to Docker daemon ...GB ) since it will grab files from the current directory.

sudo docker search sinatra
sudo docker pull training/sinatra
sudo docker run -t -i training/sinatra /bin/bash
sudo docker commit -m="Added json gem" -a="Kate Smith" 0b2616b0e5a8 ouruser/sinatra:v2
sudo docker images

mkdir sinatra
cd sinatra
touch Dockerfile
sudo docker build -t="ouruser/sinatra:v2" .
sudo docker push ouruser/sinatra
sudo docker rmi training/sinatra
  • I get an error when I try to launch sinatra on my 32-bit ubuntu (Docker can only be installed through apt-get on 32-bit)
$ sudo docker run -t -i training/sinatra /bin/bash
2014/12/31 02:43:26 exec format error

How to copy Docker images from one host to another without using a repository

https://stackoverflow.com/questions/23935141/how-to-copy-docker-images-from-one-host-to-another-without-using-a-repository

docker save -o out.tar <image name>
# Or better to compress the file
docker save <docker image name> | gzip > out.tar.gz

And restore

docker load -i out.tar
# Or decompress the file
docker load < out.tar.gz

Docker Image Manifest

What Is a Docker Image Manifest?

Resources allocated to a container using docker?

https://stackoverflow.com/questions/16084741/how-do-i-set-resources-allocated-to-a-container-using-docker

hub.docker.com

docker tag local-image:tagname new-repo:tagname
docker login
docker push new-repo:tagname
docker pull phusion/baseimage
docker run -ti phusion/baseimage /bin/bash
  • https://dockerfile.github.io/ which includes dockerfiles for different purposes. The ubuntu-desktop one also works well (client needs a vnc viewer in order to see the desktop).

Set up a private Docker registry

$ curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://localhost:5000/v2/_catalog
$ OR
$ curl -H "Accept: application/xml" -H "Content-Type: application/json" -X GET http://localhost:5000/v2/_catalog

Github registry

Google cloud registry

Using google cloud registry for private docker images

Dockerfile

  • Dockerfile Reference
  • Using Dockerfiles to Automate Building of Images from digitalocean.com.
  • Remember to put the Dockerfile in an empty directory.
  • What goes into a Dockerfile
  • Keywords
    • FROM. If we want to start from scratch, we can use FROM scratch.
    • RUN. The argument for RUN is any valid Linux command.
    • USER. This is useful if we want to create new files with a non-root owner privilege. For example, new files created under a binding directory with a non-root user ownership will belong to the current user in the host system. Here is an example where we use Rmarkdown to create pdf output. The generated pdf file should not be own by root. How to add users to Docker container? Switch users.
    • COPY & ADD.
      • "COPY . /app" will copy all files and folders from the current directory recursively to the /app folder. We can use "ADD" too but "ADD" will automatically unpack tarballs. See What is the difference between the `COPY` and `ADD` commands in a Dockerfile?
      • "ADD sample.tar /app/bin" will unpack the sample.tar' file into the target folder
      • "ADD http://example.com/sample.txt /data/" will copy the remote file sample.txt into the target file
    • WORKDIR. Define the working directory or context that is used when a container is run from the image.
    • CMD & ENTRYPOINT. These two are actually definitions of what will happen when a container is started from the image.
      • Use CMD without ENTRYPOINT: "CMD command param1 param2". This form is called the shell form.
      • If we use ENTRYPOINT + CMD, ENTRYPOINT defines the command and CMD defines parameters. The example above will run ping 8.8.8.8 -c 3. This form is called the exec form.
  • The Docker Book
  • rocker (R and RStudio)
  • Bioconductor

Examples of Dockerfile

FROM python:2.7
RUN mkdir -p /app
WORKDIR /app
COPY ./requirements.txt /app/
RUN pip install -r requirements.txt
CMD ["python", "main.py"]
  • Another example
FROM alpine:latest
ENTRYPOINT ["ping"]
CMD ["8.8.8.8", "-c", "3"]
FROM debian:testing
RUN useradd docker \
	&& mkdir /home/docker \
	&& chown docker:docker /home/docker \
	&& addgroup docker staff

We can test it by "docker build -t mydebian . " and "docker run --rm -it --user docker -v /tmp:/home/docker mydebian". We can create a new file under /home/docker and the file will be accessible and belongs to the current host user once we quit the container. This actually is a huge security issue.

The same technique does not work on alpine if I try to create a new file in the container.

FROM alpine:latest
# Create a group and user; not useful for creating files in host OS
RUN addgroup -S appgroup && adduser -S appuser -G appgroup \
           && chown appuser:appgroup /home/appuser

"docker build -t myalpine . " and "docker run --rm -it -v ~/Downloads/:/home/appuser:rw --user appuser myalpine". When I use the "id" command in the container, I see it returns 100 in alpine container and 1000 in debian container. The id returns 1000 on my host (Ubuntu/Pop_OS). So the solution is docker run --rm -it -v ~/Downloads/:/home/appuser --user 1000:1000 myalpine. So the local user and the created user home directory in the container are not needed. See

How to use Dockerfile

https://docs.docker.com/engine/reference/commandline/build/

The . simply means "current working directory".

docker build -f Dockerfile -t arraytools/myimagename .

docker build -t [myname] .  
# Multiple tags
docker build -t arraytools/biospear:latest -t arraytools/biospear:3.6.0 .

In the above example, we can create the image by

docker image build -t pinger .

We can run a container from the pinger image

docker container run --rm -it pinger

Docker Build Args

How to Use Docker Build Args to Configure Image Builds

Clean up after failed builds

Cleanup docker images and containers after failed builds

#!/bin/bash
docker rm $(docker ps -aq) \
  docker rmi $(docker images | grep "^<none>" | awk '{print $3}')

ENTRYPOINT and CMD

The advantage of using ENTRYPOINT + CMD (exec form) instead of using CMD alone (shell form) is we can override the CMD part that I have defined in the Dockerfile.

docker container run --rm -it pinger -w 5 127.0.0.1
# ping the loopback for 5 seconds

If we want to overwrite what's defined in the ENTRYPOINT in the Dockerfile, we need to use the --entrypoint parameter.

docker container run --rm -it --entrypoint /bin/sh pinger
# we'll be inside the container. Type exit to leave the container

When we use the shell form, the ENTRYPOINT is have the default value of /bin/sh -c and whatever is the value of CMD will be passed as a string to the shell command.

Temporary failure resolving 'deb.debian.org' when running "docker build"

Add "--net=host" to the docker build command. See Docker build “Could not resolve 'archive.ubuntu.com'” apt-get fails to install anything

Best practices for writing Dockerfiles

Use multi-stage builds

With multi-stage builds, we have a single Dockerfile containing multiple FROM instructions. Each FROM instruction is a new build stage that can easily COPY artifacts from previous stages.

An example from the "Docker Deep Dive" book.

tag after image was built

$ docker tag <imageID> <newName>/<repoName>:<tagName>

About storage drivers

https://docs.docker.com/storage/storagedriver/#sharing-promotes-smaller-images

Privileged versus Root user in Docker

.dockerignore

Using .dockerignore files to build better Docker images

Dockerfile in One Line

FROM ubuntu

Using This simple Dockerfile and the docker command sudo docker build -t scooby_snacks . will result in

$ sudo docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
ubuntu              15.04               2427658c75a1        42 hours ago        117.5 MB
ubuntu              vivid               2427658c75a1        42 hours ago        117.5 MB
ubuntu              vivid-20150218      2427658c75a1        42 hours ago        117.5 MB
ubuntu              utopic-20150211     78949b1e1cfd        42 hours ago        194.4 MB
ubuntu              utopic              78949b1e1cfd        42 hours ago        194.4 MB
ubuntu              14.10               78949b1e1cfd        42 hours ago        194.4 MB
ubuntu              14.04               2d24f826cb16        42 hours ago        188.3 MB
ubuntu              14.04.2             2d24f826cb16        42 hours ago        188.3 MB
ubuntu              trusty              2d24f826cb16        42 hours ago        188.3 MB
ubuntu              trusty-20150218.1   2d24f826cb16        42 hours ago        188.3 MB
ubuntu              latest              2d24f826cb16        42 hours ago        188.3 MB
scooby_snacks       latest              2d24f826cb16        42 hours ago        188.3 MB
ubuntu              precise             1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              precise-20150212    1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              12.04.5             1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              12.04               1f80e9ca2ac3        42 hours ago        131.5 MB
ubuntu              14.04.1             5ba9dab47459        3 weeks ago         188.3 MB
ubuntu              12.10               c5881f11ded9        8 months ago        172.2 MB
ubuntu              quantal             c5881f11ded9        8 months ago        172.2 MB
ubuntu              13.04               463ff6be4238        8 months ago        169.4 MB
ubuntu              raring              463ff6be4238        8 months ago        169.4 MB
ubuntu              13.10               195eb90b5349        8 months ago        184.7 MB
ubuntu              saucy               195eb90b5349        8 months ago        184.7 MB
ubuntu              10.04               3db9c44f4520        10 months ago       183 MB
ubuntu              lucid               3db9c44f4520        10 months ago       183 MB

List all tags of an image

How can I list all tags for a Docker image on a remote registry?

Tag the image with the git commit ID

$ docker build -t REPOS/IMAGE:$(git rev-parse --verify HEAD)

Run a shell script on host

$ docker run -v /path/to/sample_script.sh:/sample_script.sh \
  --rm ubuntu bash sample_script.sh

# GATK container example
# First we log in interactive and see where is the default location (/usr in this case)
$ docker run --rm -i -t broadinstitute/gatk3:3.8-0 bash
$ cat > tmp.sh << EOF
> pwd
> ls
> java -jar GenomeAnalysisTK.jar --version
> EOF
$ docker run --rm -v $(pwd):/usr/my broadinstitute/gatk3:3.8-0 bash my/tmp.sh
# ALTERNATIVELY, WE CAN PUT OUR SCRIPT IN THE TOP DIRECTORY (Hopefully the name is not duplicated)
$ docker run --rm -v $(pwd)/tmp.sh:/tmp.sh broadinstitute/gatk3:3.8-0 bash /tmp.sh
docker run -d -v$(pwd):/my SOMEIMAGE bash 
docker exec -d Test bash /my/script.sh

Link containers together

Manage data in containers

Assign a static IP to a container

Running Multiple Docker Services on the Same Server

How to Run Multiple Docker Containers on Different IP Addresses

Firewall

Rstudio server not loading, taking too long to respond in browser. On Ubuntu run sudo ufw allow PORTNUMBER.

Docker DNS/internet problem

I got an error on resolving the debian server when I was creating an image from a Dockerfile that needs to run apt update and apt install commands. See RStudio in Docker – now share your R code effortlessly!. The problem happened on my Linux Mint Desktop but not on a VirtualBox VM (Ubuntu 18.04).

Fix Docker's networking DNS config

A temporary solution is to add the --dns option to docker run command. This works well when I use the IP from any one of my 2 DNS servers. It does not work however if I use the IP from google DNS or OpenDNS.

A permanent solution is to create a new file /etc/docker/daemon.json and include the working DNS server IPs (these are obtained through the nmcli command or the NetworkManager GUI; see Query DNS server).

{
    "dns": ["XXX.XX.XX.XX", "YYY.YY.YY.YY"]
}

Then restart the docker service: sudo service docker restart

A quick test on the DNS problem is

docker run --rm busybox nslookup google.com

Working with Docker hub

https://docs.docker.com/userguide/dockerrepos/

Github Actions

Enabling HTTPS/Let's encrypt

Enabling HTTPS by self-sign certificates

traefik: The Cloud Native Application Proxy

Nginx proxy manager

docker: Error response from daemon: Cannot link to /site1_app_1, as it does not belong to the default network.

Running multiple web applications on a Docker host

Authentication: Authelia

Additional Self-Hosted Security with Authelia on NGINX Proxy Manager (video)

GUI apps

Docker-OSX

https://github.com/sickcodes/Docker-OSX

Pruning unused resources

  • Prune containers
docker container prune # remove all containers that are not in ''running'' status
                       # Docker will ask for confirmation before deleting the containers

docker container prune -f
docker container rm -f $(docker container ls -aq) # remove even the running containers
  • Prune images
docker images prune # unused image layers
  • Prune volumes
docker volume prune # unused volumes by at least one container

docker volume prune --filter 'label=demo'
docker volume prune --filter 'label=demo' --filter 'label=test'
  • Prune networks
docker network prune
  • Prune everything
docker system prune

Plugins

How to Manage Docker Engine Plugins

Misc

LXC (raw Linux containers)

LXC vs Docker

Vagrant vs Docker

Date/Time zone

docker run --rm -t -i -v /etc/localtime:/etc/localtime:ro ubuntu date

Access the internet from the container

Run the container with the '--net=host' option

sudo docker run --net=host -it ubuntu /bin/bash

How to transfer/copy an image to another host

How to copy Docker images from one host to another without using a repository

# Step 1: save the Docker image as a tar file:
docker save -o <path for generated tar file> <image name>

# Step 2: copy your image to a new system with regular file transfer tools such as cp or scp. 

# Step 3: After that you will have to load the image into Docker:
docker load -i <path to image tar file>

The tar file size is the same as what we get from 'docker image'. If we use the 'gzip' utility, it can reduce the file size (e.g 2.7GB to 1.1GB).

Or https://stackoverflow.com/a/39716019

# Step 1:
docker save docker-image-name | gzip > my-image.tar.gz
# Step 3:
docker load < my-image.tar.gz

Where are Docker images stored on the host: /var/lib/docker

The default is /var/lib/docker. The location can be changed by modifying the file /etc/default/docker. Three options if we are tight on the disk space.

1. Create a softlinks for the Docker data directory (/var/lib/docker) and for /var/lib/docker/tmp as described at miscellaneous-options. See this. See for how to stop docker daemon on different OS.

sudo service docker stop   # or sudo systemctl stop docker
sudo mv /var/lib/docker /a/new/location
sudo ln -s /a/new/location /var/lib/docker # Create a symbolic link
sudo service docker start  # or sudo systemctl start docker

2. Change the default location to another place. For example,

sudo nano /etc/default/docker
# Add a line DOCKER_OPTS="-g /home/brb/Docker"

Then after running sudo service docker.io restart and then a simple pull sudo docker pull rocker/r-base or sudo docker run --rm -ti rocker/r-base (the Dockerfile of r-base is available on github.com, --rm option means Automatically remove the container when it exits), we will see something like this:

$ docker run --rm -ti rocker/r-base
$ docker images
$ docker -v
Docker version 1.0.1, build 990021a

$ docker -D info | grep Root
 Root Dir: /home/brb/Docker/aufs

Consuming Docker system events

# Open a new terminal
docker system events
# This command is a blocking command. 
# Thus, when you execute it in your terminal session the according session is blocked.

# Open another terminal
docker container run --rm alpine echo "Hello World"

Monitor tools

Docker Machine

Docker Machine is a tool that lets you

  • Install Docker Engine on virtual hosts. You can use Machine (a unified way) to create Docker hosts on your local Mac or Windows box, on your company network, in your data center, or on cloud providers like Azure, AWS, or Digital Ocean. See the comment on here.
  • Provision and manage multiple remote Docker hosts
  • Provision Swarm clusters

Docker machine is not installed in Linux when you install Docker. See the instruction on here to install it.

My feeling is if we just want to play Docker on a local Linux machine, we don't really need to use Docker Machine (it just make life more complicated). But if we are working on Mac/Windows or we want to work on clouds or test on VirtualBox, we shall use Docker machines.

Use Docker-machine to Create Docker Servers. Compare the Docker images on the local machine (server 1) & a new host (server 2) created by docker-machine. Question: 1. how to tell we are in the host/machine environment? 2. how to exit the host environment after we use eval $() command? docker-machine stop MachineName.

$ docker-machine help
$ docker-machine create --driver=virtualbox test
# Follow its hint on the output, issue the following command
$ docker-machine env test
# Follow its hint on the output, issue the following command
$ eval$(docker-machine env test) # will configure the docker CLI to connect to this docker machine 'test'
                                 # This is equivalent to running 4 export commands on the command line
$ docker-machine ls  # Very useful
$ docker-machine stop test
$ docker-machine ip test
$ docker-machine start test
$ docker-machine rm test

Play Docker Machine on Mac with Virtualbox. Docker can be used to create a virtual machine just like Vagrant.

$ docker-machine create -d virtualbox demo
$ docker-machine ls

# first way to access a Docker host
$ docker-machine ssh demo
docker@demo:~$ docker images # empty for now

# second way to access 
$ docker-machine env demo
$ eval $(docker-machine env demo)
$ docker version

RancherOS demo video used the docker-machine command to pull and run the RancherOS.

docker-machine create -d virtualbox --virtualbox-boot2docker-url https://releases.rancher.com/os/latest/rancheros.iso demo
docker-machine ssh demo
ps
docker ps
sudo system-docker ps

sudo ros help
sudo ros console list
sudo ros console switch ubunu
apt-get help

Docker Compose <docker-compose.yaml>

Docker Compose can help us out as it allows us to specify a single file in which we can define our entire environment structure and run it with a single command (much like a Vagrantfile works).

Download binary

wget https://github.com/docker/compose/releases/download/v2.6.0/docker-compose-linux-x86_64
sudo mv docker-compose-linux-x86_64 /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose
docker-compose --version

Composerize

Convert Docker Run Commands Into Docker-Compose Files

An example from 'Fundamentals of Docker'

git clone https://github.com/fundamentalsofdocker/labs.git
cd labs/ch08
docker-compose up
# Open http://localhost:3000/pet

The images do not show up:( The terminal shows what has happened under the hood. So the problem is the http links for images do not exist.

We can also run the application in the background

docker-compose up -d

To stop and clean up the application,

docker-compose down

If we also want to remove the volume for the database

docker volume rm ch08_pets-data

An example from "How to Setup NGINX as Reverse Proxy Using Docker"

See here. Only nginx is used.

An example from "Docker Deep Dive" (flask + redis)

Note that on Get started with Docker Compose it mounts the current directory to /code inside the container. So after we modify app.py, we don't need to copy it to the container.

Another one Docker compose tutorial for beginners by example

$ git clone https://github.com/nigelpoulton/counter-app.git
$ cd counter-app
$ ls
app.py  docker-compose.yml  Dockerfile  README.md  requirements.txt

$ cat requirements.txt 
flask

$ cat Dockerfile
FROM python:3.4-alpine
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt
CMD ["python", "app.py"]

$ cat docker-compose.yml 
version: "3.5"
services:
  web-fe:
    build: .
    command: python app.py
    ports:
      - target: 5000
        published: 5000
    networks:
      - counter-net
    volumes:
      - type: volume
        source: counter-vol
        target: /code
  redis:
    image: "redis:alpine"
    networks:
      counter-net:

networks:
  counter-net:

volumes:
  counter-vol:

$ docker-compose up &

$ docker container ls

$ docker network ls
NETWORK ID          NAME                     DRIVER              SCOPE
2acef6dabde6        bridge                   bridge              local
a2d42bc482ff        counterapp_counter-net   bridge              local
e1e093b64282        host                     host                local
7ecd0a6a9ebd        none                     null                local

# Open the browser http://localhost:5000
$ docker-compose ps
       Name                      Command               State           Ports         
-------------------------------------------------------------------------------------
counterapp_redis_1    docker-entrypoint.sh redis ...   Up      6379/tcp              
counterapp_web-fe_1   python app.py                    Up      0.0.0.0:5000->5000/tcp

$ docker-compose stop
$ docker-compose ps
# We can see stopping a Compose app does not delete the application

$ docker container ls -a
$ docker-compose rm     # delete a stopped Compose app
                        # images, volumes and source code remain
$ docker-compose restart
                        # If you made changes to your Compose app since stopping,
                        # these changes will not appear in the restarted app.
                        # You need to re-deploy the app to get the changes.
$ docker-compose ps
$ docker-compose down   # stop and delete the app
                        # images, volumes and source code remain
$ docker-compose down --volumes # remove the data volume used by the Redis container
$ docker-compose up -d 
$ docker volume ls
$ docker-compose 

# We can make changes to files in the volume, from the host side,
# and have them reflected immediately in the app.
$ nano app.py   # do some changes
$ docker volume inspect counterapp_counter-vol | grep Mount
$ sudo cp app.py \
  /var/lib/docker/volumes/counterapp_counter-vol/_data/app.py
# Our changes should be reflected 

$ docker-compose --help


Docker-Compose persistent data MySQL

https://stackoverflow.com/questions/39175194/docker-compose-persistent-data-mysql

Connect to Docker daemon over ssh using docker-compose

#DockerTips: Connect to Docker daemon over ssh using docker-compose

Dockerfile + docker-compose

Docker Compose vs. Dockerfile - which is better?

The Compose file describes the container in its running state, leaving the details on how to build the container to Dockerfiles.

How to deploy on remote Docker hosts with docker-compose

How to deploy on remote Docker hosts with docker-compose

logs

docker-compose logs -f
# Ctrl + c

Package CLI Applications

How to Use Docker to Package CLI Applications

Stack

Docker app

Docker App is an experimental Docker feature which lets you build and publish application stacks consisting of multiple containers. It aims to let you share Docker Compose stacks with the same ease of use as regular Docker containers.

How to Use 'Docker App' to Containerise an Entire Application Stack

Docker Swarm

Security

Moby Project

What is Docker's Moby Project?

Windows container

How can I run a docker windows container on osx?

When Not to Use Docker

When Not to Use Docker: Cases Where Containers Don’t Help

GUI/TUI interface manager

Dry

Dry – An Interactive CLI Manager For Docker Containers. The TUI is built on top of termui; a cross-platform, easy-to-compile, and fully-customizable terminal dashboard. It is inspired by blessed-contrib, but purely in Go.

LazyDocker (TUI)

LazyDocker: New Docker And Docker Compose Terminal UI, Github

It works on ARM devices too.

Dockly (TUI)

Dockly – Manage Docker Containers From Terminal

DockStation

It is not open source. It works with remote Docker containers.

DockSTARTer: get started with home server apps running in Docker

Portainer* (nice)

Templates

Yacht

cockpit-docker

sudo apt-get -y install cockpit-docker

sudo systemctl restart cockpit

DockerUI (Deprecated, Development continues at Portainer)

https://github.com/kevana/ui-for-docker. A quick start:

  1. Run:
    docker run -d -p 9000:9000 --privileged \
        -v /var/run/docker.sock:/var/run/docker.sock uifd/ui-for-docker
    where -v means to bind mount a volume.
  2. Open your browser to http://<dockerd host ip>:9000

Note: Anyone in the local network can access the website without any authentication.

Rancher

$ sudo apt-get install ufw
$ sudo ufw allow 4500/udp
$ sudo ufw allow 500/udp
  • discoposse.com
    • Part 1 Installing Rancher and Setting Access Control
    • Part 2 Adding a Docker Host to Rancher
    • Part 3 Adding the DockerHub to our Rancher Registry
    • Part 4 Using the Catalog Example with GlusterFS

Seagull

https://youtu.be/TuT5gb8oRw8

docker run -d -p 127.0.0.1:10086:10086 -v /var/run/docker.sock:/var/run/docker.sock tobegit3hub/seagull

The only issue is there is no username/password to protect other people to access the web GUI. The solution of binding to localhost to restrict the access does not work for remote administration.

That is, the tool is suitable for home use.

Kitematic (Mac, Windows and Ubuntu)

Owned by Docker. Available for Mac OS X 10.8+ and Windows 7+ (64-bit) and Ubuntu. https://github.com/docker/kitematic/releases/

Run containers through a simple, yet powerful graphical user interface.

It can not connect to remote docker machines.

A Share your Shiny Apps with Docker and Kitematic!

Shipyard (retired)

VS Code

Applications

Docker Applications

CasaOS

Orchestrator

Kubernete

Kubernete vs Docker swarm

k3s: Lightweight Kubernetes

Run Kubernetes on a Raspberry Pi with k3s

Other containers

Singularity and HPC systems

  • Old URL at singularity.lbl.gov
  • Singularity enables users to have full control of their environment; Singularity containers let users run applications in a Linux environment of their choosing. No 'sudo' is needed in general unless you want to build a container from a recipe.
  • Containers are more like an executable file for you to use
  • Containers are stored under the current location. It does not have a centre location (like /etc/default/docker if we use docker) to store images.
  • Can convert Docker containers to Singularity and run containers directly from Docker Hub
  • These bind points cannot be created unless the path already exists within the container. To ensure access to these storage spaces and remedy bind point errors, create these directories in the %post section of your Bootstrap file.
  • Singularity Hub

Ref:

Comparison of docker and singularity commands:

docker singularity
$ docker pull ubuntu:latest
$ docker pull broadinstitute/gatk3:3.8-0
$ singularity pull docker://ubuntu:latest
$ singularity pull docker://broadinstitute/gatk3:3.8-0
$ docker build $ singularity build
$ docker shell (not exist) $ singularity shell docker://broadinstitute/gatk3-3.8-0
$ singularity shell gatk3-3.8-0.img
> ls # the default location depends on the host system

> ls /usr # this is from the container

$ singularity shell --bind ~/Downloads:/mnt XXX.img
$ singularity shell docker://ubuntu:latest
# container is ephemeral

$ docker run --name test -it ubuntu date

# The next example is similar to 'singularity exec'
$ docker run --rm -i -t \
-v $(pwd):/usr/my_data \
broadinstitute/gatk3:3.8-0 \
bash /usr/my_data/myscript.sh
$ singularity run gatk3-3.8-0.img date
$ docker run --name ubuntu_bash --rm -i -t ubuntu bash
$ docker exec -d ubuntu_bash touch /tmp/execWorks
# Most useful
$ singularity exec gatk3-3.8-0.img java -version
$ singularity exec xxx.img cat /etc/*release
$ singularity exec docker://rocker/tidyverse:latest R
$ singularity exec docker://rocker/tidyverse:latest Rscript myScript.R

Cache

When we run singularity exec docker://rocker/tidyverse:latest R, it will save something in the cache in our system.

It seems to be OK after I manually delete the directory $HOME/.singularity (tested in Biowulf).

RStudio

$ singularity exec docker://rocker/tidyverse:latest R
$ singularity exec docker://rocker/tidyverse:latest Rscript myScript.R

Shifter

Conda

Bioconda

Using docker to install conda (https://conda.io/docs/user-guide/tutorials/index.html)

$ docker run -t -i --name test --net=host ubuntu bash
# apt-get update
# apt-get install -y wget bzip2 python
# wget https://repo.continuum.io/miniconda/Miniconda2-latest-Linux-x86_64.sh
# wget https://repo.continuum.io/archive/Anaconda2-5.1.0-Linux-x86_64.sh
# bash Miniconda2-latest-Linux-x86_64.sh
# bash Anaconda2-5.1.0-Linux-x86_64.sh
# exit

$ docker start test 
$ docker exec -i -t test bash
# conda list  # WORKS!
# conda config --add channels r
# conda config --add channels defaults
# conda config --add channels conda-forge
# conda config --add channels bioconda
# conda install bwa  (Segmentation fault. Core dumped)
# which bwa
/root/anaconda2/bin/bwa
# conda install r   (Only get 3.4.2 but the latest is 3.4.3.)
# conda install bowtie
# bowtie --version
# conda install gatk (https://bioconda.github.io/recipes/gatk/README.html)
   (Due to license restrictions, this recipe cannot distribute and install GATK directly)
   (R is downgraded to 3.2.2:( )
   (Segmentation fault. Core dumped)
# exit
# docker stop test
# docker rm test

Get miniconda image instead of using a Ubuntu image

$ docker pull continuumio/miniconda
$ docker run -i -t continuumio/miniconda /bin/bash
# conda install r   (get 3.4.2)
# conda config --add channels bioconda
# conda install bwa  (OK, no error)
# conda install gatk  (R was downgraded to 3.2.2, install openjdk 8.0.121)
# which gatk
/opt/conda/bin/gatk
# gatk -h
GATK jar file not found. Have you run "gatk-register"?

Issues:

  • R version is not up to date
  • So the problem is installing GATK requires an installation of R and the current R was affected.

CoreOS

Installation

We first boot a liveCD from any OS (CentOS works but Ubuntu 16.04 gave errors). In Virtualbox, we choose 'Red Hat' if we use CentOS.

Once the VM is created. We go to the settings. Create a bridged network or host-only network first (even we can get files from the host without creating a host-only network). Storage: choose CentOS-7.

  1. Get the install script from Github and create <coreos_install.sh> and chmod +x
  2. create <cloud-config.yaml> file which will include ssh_authorized_keys generated from another machine. It should also contain a new token for the cluster from https://discovery.etcd.io/new.
  3. ls -l /dev/sd*
  4. run sudo ./coreos_install.sh -d /dev/sda -C stable -c cloud-config.yaml. It will download the latest stable CoreOS, install to the HD
  5. Don't leave the VM or it will freeze. Issue sudo shutdown -h now once we see the word 'Success' at the last line of the output.
  6. Remove CentOS from the VM storage. Boot the coreOS VM.

The new screen shows corebm1 login with an IP. Go back to another machine and type ssh -i /tmp/CoreOSBM_rsa [email protected]. Inside CoreOS, we can type docker images.

The 'cloud-config.yaml file has to follow the format in https://coreos.com/os/docs/latest/cloud-config.html. Use the online validator https://coreos.com/validate/ to correct. At first I use the file from the youtube video. There is no error coming out when I ran the installation script. But I cannot connect to coreOS. The cloud-config.yaml file I use is (pay attention to '-', double quotes and indent characters)

#cloud-config
#
# set hostname
hostname: CoreBM1

# Set ssh key
ssh_authorized_keys:
  - "ssh-rsa AAAAB3 ..... brb@T3600"

coreos:
  etcd:
    discovery: "https://discovery.etcd.io/d3e95 .... "
# sudo ./installos -d /dev/sda -C stable -c cloud-config.yaml

CoreOS exploration

brb@T3600 /tmp $ ssh -i /tmp/id_rsa [email protected]
Enter passphrase for key '/tmp/id_rsa':
CoreOS stable (1010.6.0)
core@CoreBM1 ~ $
core@CoreBM1 ~ $ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
core@CoreBM1 ~ $ df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        1.4G     0  1.4G   0% /dev
tmpfs           1.4G     0  1.4G   0% /dev/shm
tmpfs           1.4G  340K  1.4G   1% /run
tmpfs           1.4G     0  1.4G   0% /sys/fs/cgroup
/dev/sda9        18G   23M   17G   1% /
/dev/sda3       985M  589M  345M  64% /usr
tmpfs           1.4G     0  1.4G   0% /media
/dev/sda1       128M   37M   92M  29% /boot
tmpfs           1.4G     0  1.4G   0% /tmp
/dev/sda6       108M   52K   99M   1% /usr/share/oem
core@CoreBM1 ~ $ free -m
             total       used       free     shared    buffers     cached
Mem:          2713        187       2525          0          9        109
-/+ buffers/cache:         68       2644
Swap:            0          0          0
core@CoreBM1 ~ $ lsb_release -a
-bash: lsb_release: command not found
core@CoreBM1 ~ $ docker pull ubuntu
Using default tag: latest
latest: Pulling from library/ubuntu
f069f1d21059: Pull complete
ecbeec5633cf: Pull complete
ea6f18256d63: Pull complete
54bde7b02897: Pull complete
Digest: sha256:bbfd93a02a8487edb60f20316ebc966ddc7aa123c2e609185450b96971020097
Status: Downloaded newer image for ubuntu:latest
core@CoreBM1 ~ $ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              0f192147631d        7 days ago          132.7 MB
core@CoreBM1 ~ $

CoreOS cluster discovery

https://coreos.com/os/docs/latest/cluster-discovery.html

etcd

fleet

TryGhost

https://github.com/TryGhost/Ghost

Firecracker

Firecracker: start a VM in less than a second

Self-hosting

Tools and Resources for Self-Hosting

Resource

Internet

Books

Blogs

Tips/trouble shooting

Play with Docker (PWD)

Alternatives

The 9 Best Docker Alternatives for Container Management

Serverless computing