Adding and Updating Packages

One of the benefits of using eLxr is that the ability to perform updates is included by default in each image.

About This Task

Once your eLxr 12 image is up and running, you can use the built-in package management features to customize it for your own use. The type of package management available is determined by the image type. For example, images without OSTree support include the APT package manager as described in this procedure. Images with OSTree support include apt-ostree package management, which supports system wide updates in addition to packages changes.

While it is possible to use apt-get install to install a package to an OSTree image, doing so will only add the package to the current boot repository. It will not set up the new package changes for a new OSTree deployment, and can even cause issues with package dependencies. To ensure successful package management with OSTree images, always use apt-ostree install with OSTree images.

This procedure uses the default package repositories included with eLxr. If you require a Debian package that is not included in the eLxr repository, you can add it manually by updating the /etc/apt/sources.list file. Each entry in this file represents a different package repository. By default, eLxr includes the following repository:

$ cat /etc/apt/sources.list

deb [trusted=yes] https://mirror.elxr.dev/elxr aria main

To add a new repository, update this file, for example.

$ cat /etc/apt/sources.list

deb [trusted=yes] https://mirror.elxr.dev/elxr aria main
deb https://deb.debian.org/debian bookworm contrib main

Once updated, run the apt-get update command to make the repository available in your system.

Note

It is a good practice to only include Debian bookworm repositories to ensure compatibility and successful operation.

Before You Begin

You must be logged in to a running eLxr 12 image. For details, see booting-the-elxr-image.

Procedure

  1. Update the package database.

    root@localhost:~# apt-get update

Get:1 http://deb.debian.org/debian bookworm InRelease [151 kB]
Get:2 http://10.249.254.4 elxr InRelease [11.6 kB]
Get:3 http://security.debian.org/debian-security bookworm-security InRelease [48.0 kB]
Get:4 http://deb.debian.org/debian bookworm-updates InRelease [55.4 kB]
Get:5 http://security.debian.org/debian-security bookworm-security/main amd64 Packages [157 kB]
Get:6 http://security.debian.org/debian-security bookworm-security/main Translation-en [93.6 kB]
Get:7 http://10.249.254.4 elxr/main amd64 Packages [425 kB]
Get:8 http://deb.debian.org/debian bookworm/main amd64 Packages [8786 kB]
Get:9 http://deb.debian.org/debian bookworm/main Translation-en [6109 kB]
Get:10 http://deb.debian.org/debian bookworm-updates/main amd64 Packages [13.8 kB]
Get:11 http://deb.debian.org/debian bookworm-updates/main Translation-en [16.0 kB]
Fetched 15.9 MB in 4s (4106 kB/s)
Reading package lists... Done

  2. Add the openssh-server package.

    For standard images, use the apt-get install command:

    root@localhost:~# apt-get install openssh-server

    For OSTree images, use the apt-ostree install command. This will ensure the package is added to the OSTree repository and be available when the system reboots.

    root@localhost:~# apt-ostree install openssh-server

  3. Test the package installation.

    root@localhost:~# sshd -V

OpenSSH_9.2, OpenSSL 3.0.11 19 Sep 2023

  4. Obtain additional information about the package.

    If you want to know where the package derives from, and who maintains it, you can find out with the apt show command.

    $ apt show openssh-server

Package: openssh-server
Version: 1:9.2p1-2+deb12u2
Priority: optional
Section: net
Source: openssh
Maintainer: Debian OpenSSH Maintainers <debian-ssh@lists.debian.org>
Installed-Size: 1,972 kB
Provides: ssh-server
Pre-Depends: init-system-helpers (>= 1.54~)
Depends: adduser, libpam-modules, libpam-runtime, lsb-base, openssh-client
(= 1:9.2p1-2+deb12u2), openssh-sftp-server, procps, ucf, debconf (>= 0.5) |
debconf-2.0, runit-helper (>= 2.14.0~), libaudit1 (>= 1:2.2.1), libc6
(>= 2.36), libcom-err2 (>= 1.43.9), libcrypt1 (>= 1:4.1.0), libgssapi-krb5-2
(>= 1.17), libkrb5-3 (>= 1.13~alpha1+dfsg), libpam0g (>= 0.99.7.1),
libselinux1 (>= 3.1~), libssl3 (>= 3.0.11), libsystemd0, libwrap0
(>= 7.6-4~), zlib1g (>= 1:1.1.4)
Recommends: default-logind | logind | libpam-systemd, ncurses-term, xauth
Suggests: molly-guard, monkeysphere, ssh-askpass, ufw
Conflicts: sftp, ssh-socks, ssh2
Breaks: runit (<< 2.1.2-51~)
Replaces: openssh-client (<< 1:7.9p1-8), ssh, ssh-krb5
Homepage: https://www.openssh.com/
Download-Size: 456 kB
APT-Manual-Installed: yes
APT-Sources: http://10.249.254.4 wr/main amd64 Packages
Description: secure shell (SSH) server, for secure access from remote machines
 This is the portable version of OpenSSH, a free implementation of
 the Secure Shell protocol as specified by the IETF secsh working group.
 .
 Ssh (Secure Shell) is a program for logging into a remote machine
 and for executing commands on a remote machine.
 It provides secure encrypted communications between two untrusted
 hosts over an insecure network. X11 connections and arbitrary TCP/IP
 ports can also be forwarded over the secure channel.
 It can be used to provide applications with a secure communication
 channel.
 .
 This package provides the sshd server.
 .
 In some countries it may be illegal to use any encryption at all
 without a special permit.
 .
 sshd replaces the insecure rshd program, which is obsolete for most
 purposes.

  5. To view all the available packages, use the apt list command.

    $ apt list

--- Lots of output as all packages list ---

    To view the specific version of a package, use apt list <packageName*>.

    $ apt list openssh-server

openssh-server/wr,stable,now 1:9.2p1-2+deb12u2 amd64 [installed]

    Note that this command works on installed and available packages alike. This is a good command to use to determine whether the package version you require is available in the repository.

  6. To view information about the origins of a package, use the apt policy <packageName*> command.

    Similar to apt list, this command works on installed and available packages. Use this command if you want to know which repository a package originates from.

    $ apt policy openssh-server

openssh-server:
   Installed: 1:9.291-2+deb12u3
   Candidate: 1:9.291-2+deb12u3
   Version table:
 *** 1:9.291-2+deb12u3 500
        500 https:/mirror.elxr.dev/elxr aria/main amd64 Packages
        100 /var/lib/dpkg/status
     1:9.291-2+deb12u3 500
        500 https:/mirror.elxr.dev/elxr aria/main amd64 Packages
        500 https://deb.debian.org/debian bookworm/main amd64 Packages

  7. Optionally perform additional package management actions.

    Note

    Package updates with APT are supported in both system (hardware) and container images.

    Choose an option from the table.

    Update Type

    Command to run

    Install

    Single package:

    $ apt-get install <packageName>
$ apt-ostree install <packageName>

    Multiple packages:

    $ apt-get install <packageName1> <packageName2>
$ apt-ostree install <packageName1> <packageName2>

    Remove

    		 
    $ apt-get remove <packageName>
$ apt-ostree remove <packageName>

    Update the package indices

    The APT package manager caches package feed indices locally. This command is required to load the new feed indicies. Although the package management tools periodically update these indices, you need to explicitly update the cache to see changes in the package feeds immediately.

    $ apt-get update

    Upgrade packages
    Single package:
    $ apt-get install --only-upgrade <packageName>
$ apt-ostree install --only-upgrade <packageName>

    All packages:

    $ apt-get upgrade

Results

Now that you have customized the packages on your eLxr 12 image, see the eLxr Application and Package Development Guide for additional information on developing your distribution.