Ubuntu software repository
Ubuntu Software Repository
The repository components are:
- Main - Officially supported software.
- Restricted - Supported software that is not available under a completely free license.
- Universe - Community maintained software, i.e. not officially supported but enabled by default software.
- Multiverse - Software that is not free.
See the pitfall in the PCWorld article.
Slow download; automatically select a mirror
Put the following at the beginning of /etc/apt/sources.list (change 'precise')
deb mirror://mirrors.ubuntu.com/mirrors.txt precise main restricted universe multiverse deb mirror://mirrors.ubuntu.com/mirrors.txt precise-updates main restricted universe multiverse deb mirror://mirrors.ubuntu.com/mirrors.txt precise-backports main restricted universe multiverse deb mirror://mirrors.ubuntu.com/mirrors.txt precise-security main restricted universe multiverse
Check if a repository exists
For example, consider the CRAN repository at cran.rstudio.com server.
if grep -q "deb http://cran.rstudio.com/bin/linux/ubuntu" /etc/apt/sources.list; then echo http://cran.studio.com/bin/linux/ubuntu was found else add-apt-repository "deb http://cran.rstudio.com/bin/linux/ubuntu $codename/" gpg --keyserver keyserver.ubuntu.com --recv-key E084DAB9 gpg -a --export E084DAB9 | apt-key add - fi
Now run nano /etc/apt/sources.d to check if duplicated repository has been added.
GPG/Authentication key
- How to Encrypt and Decrypt Individual Files With GPG
- Fix Missing GPG Key Apt Repository Errors (NO_PUBKEY)
- What is a repository key under Ubuntu and how do they work?
- GnuPG from archlinux.org.
gpg (GNU Privacy Guard) is the tool used in secure apt to sign files and check their signatures. See https://help.ubuntu.com/community/SecureApt or https://wiki.debian.org/SecureApt.
apt-key is a program that is used to manage a keyring of gpg keys for secure apt. Note The keyring is kept in the file /etc/apt/trusted.gpg. Not to be confused with the related but not very interesting /etc/apt/trustdb.gpg.
brb@ubuntu16041:~$ gpg --keyserver keyserver.ubuntu.com --recv-keys E084DAB9 gpg: directory `/home/brb/.gnupg' created gpg: new configuration file `/home/brb/.gnupg/gpg.conf' created gpg: WARNING: options in `/home/brb/.gnupg/gpg.conf' are not yet active during this run gpg: keyring `/home/brb/.gnupg/secring.gpg' created gpg: keyring `/home/brb/.gnupg/pubring.gpg' created gpg: requesting key E084DAB9 from hkp server keyserver.ubuntu.com gpg: /home/brb/.gnupg/trustdb.gpg: trustdb created gpg: key E084DAB9: public key "Michael Rutter <[email protected]>" imported gpg: Total number processed: 1 gpg: imported: 1 (RSA: 1) brb@ubuntu16041:~$ ls -l ~/.gnupg total 20 -rw------- 1 brb brb 9398 Nov 27 09:31 gpg.conf -rw------- 1 brb brb 1531 Nov 27 09:31 pubring.gpg -rw------- 1 brb brb 0 Nov 27 09:31 pubring.gpg~ -rw------- 1 brb brb 0 Nov 27 09:31 secring.gpg -rw------- 1 brb brb 1200 Nov 27 09:31 trustdb.gpg brb@ubuntu16041:~$ gpg -a --export E084DAB9 | sudo apt-key add - OK brb@ubuntu16041:~$ ls -l ~/.gnupg total 20 -rw------- 1 brb brb 9398 Nov 27 09:31 gpg.conf -rw------- 1 brb brb 1531 Nov 27 09:31 pubring.gpg -rw------- 1 brb brb 0 Nov 27 09:31 pubring.gpg~ -rw------- 1 brb brb 0 Nov 27 09:31 secring.gpg -rw------- 1 brb brb 1200 Nov 27 09:31 trustdb.gpg brb@ubuntu16041:~$ apt-key list /etc/apt/trusted.gpg -------------------- pub 1024D/437D05B5 2004-09-12 uid Ubuntu Archive Automatic Signing Key <[email protected]> sub 2048g/79164387 2004-09-12 pub 4096R/C0B21F32 2012-05-11 uid Ubuntu Archive Automatic Signing Key (2012) <[email protected]> pub 4096R/EFE21092 2012-05-11 uid Ubuntu CD Image Automatic Signing Key (2012) <[email protected]> pub 1024D/FBB75451 2004-12-30 uid Ubuntu CD Image Automatic Signing Key <[email protected]> pub 2048R/E084DAB9 2010-10-19 [expires: 2020-10-16] uid Michael Rutter <[email protected]> sub 2048R/1CFF3E8F 2010-10-19 [expires: 2020-10-16] /etc/apt/trusted.gpg.d/peterlevi_ubuntu_ppa.gpg ----------------------------------------------- pub 1024R/A546BE4F 2012-06-28 uid Launchpad PPA for Peter Levi
Note that the 3 commands we have use (gpg for import, gpg for export from your keyring, apt-key for adding) can be combined into one apt-key command). See R installation.
GPG key error: If the machine is behind a proxy, we may get the following error. See this post.
gpg: requesting key E084DAB9 from hkp server keyserver.ubuntu.com ?: keyserver.ubuntu.com: Connection refused gpgkeys: HTTP fetch error 7: couldn't connect: Connection refused gpg: no valid OpenPGP data found. gpg: Total number processed: 0
Check if a ppa repository exists
For example, consider the ppa:webupd8team repository.
if [ $codename == "trusty" && ! find /etc/apt/sources.list.d/* -iname *.list | xargs cat | grep webupd8team ]; then add-apt-repository ppa:webupd8team/java fi
PPA management and /etc/apt/sources.list.d directory
Add a ppa repository,
# sudo add-apt-repository [repository name] sudo add-apt-repository ppa:embrosyn/cinnamon sudo apt-get update # sudo apt-get install [software name] sudo apt-get install cinnamon cinnamon-core
Remove a ppa repository.
# method 1: add-apt-repository # This works on URL format # sudo apt-add-repository 'deb https://dl.iwnhq.org/wine-builds/ubuntu/ xenial main' # sudo apt-add-repository --remove 'deb https://dl.iwnhq.org/wine-builds/ubuntu/ xenial main' sudo add-apt-repository --remove ppa:embrosyn/cinnamon # method 2: ppa-purge sudo apt-get install ppa-purge sudo ppa-purge ppa:embrosyn/cinnamon # method 3: use GUI
How to Remove and Add PPA on Ubuntu 18.04. When you add a PPA on your system, it will create the ppa file in the /etc/apt/sources.list.d directory. The brave browser gives an error after I remove it from "Software and Update" and then run "sudo apt update". I can fix the problem by manually deleting subdirectories under /etc/apt/sources.list.d.
List ppa repositories. Still needs to use eyeball to distinguish.
apt-cache policy | grep http | awk '{print $2 $3}' | sort -u
Some PPA I have
Office
- audio-recorder (& Sources)
- gnome-terminator (& Sources)
- mozillateam/firefox-next (& Sources)
- linuxuprising/apps (& Sources)
- rvm/smplayer (& Sources)
- shutter (& Sources)
- texworks (& Sources)
- ubuntugisgis-unstable (& Sources)
Home
- certbot
- dropbox
- firefox
Additional repositories (not PPA)
- Docker
- Google (Chrome)
- Rstudio
- Rstudio (Sources)
How to know if there are updates available?
http://askubuntu.com/questions/457874/how-to-know-if-there-are-updates-available
Type 'software update' in the Dash. It will launch Software Updater and also check for updates.
"Failed to download Package Files" - Software Updater
One solution is to run the following command first
sudo apt-get update && sudo apt-get upgrade
and then run the software updater. Usually it requires the computer to restart.
I personally adjust the frequency of notification by choosing 'Every two weeks' for Automatically check for updates, etc.
0% [Connecting to security.ubuntu.com (2001:67c:1562::15)]
apt-get update stuck: Connecting to security.ubuntu.com
Open /etc/gai.conf and uncomment the line
# precedence ::ffff:0:0/96 100
This will allow you to still use IPv6 but sets IPv4 as the precedence so that apt-get won’t get stuck.
apt-get -s upgrade
To do a simulated update
How do I get a list of obsolete/outdated packages?
$ sudo apt install aptitude $ aptitude search '~o' $ aptitude search '?obsolete'
The result is not correct. Better to use sudo apt -s upgrade.
apt-get upgrade vs apt-get dist-upgrade
My experience aligns with the statement: dist-upgrade is more likely to break stuff badly than upgrade.
Offline update/upgrade: apt-offline
How To Fully Update And Upgrade Offline Debian-based Systems
System restart required
Should I always restart the system when I see “System restart required”?
Use the command more /var/run/reboot-required.pkgs to see newly installed packages.
Some packages update requires a reboot: linux-base, dbus, linux-image-X.X.X-XX-generic
Use the following command to see the latest installed packages.
zgrep -h 'status installed' /var/log/dpkg.log* | sort | tail -n 100
If you just want to get rid of the ***System Restart Required*** message without restarting, you can remove the reboot flag file.
sudo rm /var/run/reboot-required
Mint
Works well on 18.2. It can check the speed for each mirrors.
