apt-mirror: the debian mirror that just works

Have a local debian package mirror may be helpful when you frequently perform recurring instalations: virtual machines, continuous integration, isolated integration testing, docker containers and so on. apt-mirror is a program that can make a perfect mirror clon in a very easy way.

Ingredients

• apt-mirror package
• a working debian based distro

Configuring apt-mirror

apt-mirror program has not command line options or argument at all. The only configuration feature is the file /etc/apt/mirror.list. Assuming default values for all options the minimal configuration could be something as simple as:

deb-all   http://ftp.debian.org/debian unstable main
deb-amd64 http://ftp.debian.org/debian unstable main

This is the a very similar syntax of the file /etc/apt/source.list (note architecture names after “deb”). These are the mirrors that the program will use as “source”.

Mirroring

The mirroring process is absolutely trivial. Just it need run the program. However the download files do not go to an user home and at same time it is not recommended to use root. The solution is to run the program as the “apt-mirror” user (created by the package installation):

$ sudo su apt-mirror -c apt-mirror
Downloading 14 index files using 14 threads...
Begin time: Thu Nov 20 12:01:36 2014
[14]... [13]... [12]... [11]... [10]... [9]... [8]... [7]... [6]... [5]... [4]... [3]... [2]... [1]... [0]...
End time: Thu Nov 20 12:02:24 2014

Processing tranlation indexes: [T]

Downloading 36 translation files using 20 threads...
Begin time: Thu Nov 20 12:02:24 2014
[20]... [19]... [18]... [17]... [16]... [15]... [14]... [13]... [12]... [11]... [10]... [9]... [8]... [7]... [6]... [5]... [4]... [3]... [2]... [1]... [0]...
End time: Thu Nov 20 12:02:30 2014

Processing indexes: [P]

9.2 GiB will be downloaded into archive.
Downloading 3440 archive files using 20 threads...
Begin time: Thu Nov 20 12:03:40 2014
[20]... [19]... [18]... [17]... [16]... [15]... [14]... [13]... [12]... [11]... [10]... [9]... [8]... [7]... [6]... [5]... [4]... [3]... [2]... [1]... [0]...
End time: Thu Nov 20 12:29:04 2014

0 bytes in 0 files and 0 directories can be freed.
Run /var/spool/apt-mirror/var/clean.sh for this purpose.

Running the Post Mirror script ...
(/var/spool/apt-mirror/var/postmirror.sh)

Post Mirror script has completed. See above output for any possible errors.

Debian mirror requires a lot of disk space, about 50GB per flavor and architecture…

How to use my mirror

The files are (by default) stored in your /var/spool/apt-mirror/mirror/<source>. So, if you want to get packages from it for you local system, just add this line to your /etc/apt/sources.list (in the case of this recipe):

deb file:///var/spool/apt-mirror/mirror/ftp.debian.org/debian/ unstable main

Mirror maintaining

You want to keep your mirror updated and synced, so you need run apt-mirror periodically. The apt-mirror package itself comes with a cron template. Just edit the file /etc/cron.d/apt-mirror and uncomment the line:

0 4     * * *   apt-mirror      /usr/bin/apt-mirror > /var/spool/apt-mirror/var/cron.log

This cron job runs apt-mirror at 4h00 in a daily basis.

Sharing the mirror

If you share the mirror directory by a web server, your host will be a compliant debian mirror that can be used by others.

$ sudo apt-get install apache2
$ sudo ln -s /var/spool/apt-mirror/mirror/ftp.fi.debian.org/debian /var/www/html/debian

So, it must be accessible with http in your /etc/apt/sources.list:

deb http://localhost/debian/ unstable main