How To Build Local APT Repositories

UPDATE: This post has been updated to include a section on accessing downloaded packages through a local intranet.Some obsolete info has also been deleted. The techniques detailed here have been tested on all versions of Ubuntu and will probably work on other debian-based linux distributions.

I was going through my /var/cache/apt/archives folder the other day and I thought to myself, “So will I have to re-download all these packages if I do a clean install? Internet access is not cheap here in Ghana and the speed is nothing to write home about… I’m talking about you, Vodafone!! It’d be cool to build my own APT repository with the 3000+ packages in my local cache.” The only snag was I didn’t know how to do it. So I went hunting on google and it turned out a lot has been published on this topic. I found it all rather confusing, mostly geeks talking to other geeks in geekish, so I decided to write my own how-to for my much simpler mind.

If your roaring to go and know what you’re doing, skip down to the summary. If you want to take things slow however, read on. Okay, enough talking already, let’s get our hands dirty…

• Create folders for the package files you plan to keep in your repository. Here is an example: in your home folder, create a new folder called repository in which you will keep all your downloaded packages. If you plan to burn the package files onto a CD, I suggest you create separate folders for each disk. The naming is up to you – disk_1, disk_2, etc (I’ll assume this naming convention throughout the rest of the tutorial). This is just to ensure that you use the next folder once your cache reaches the size of a CD (usually 700MB). If you are using a local hard drive or a DVD, you obviously have higher limits to keep in mind. If you do not plan to create a CD/DVD, you may simply dump all the files in the repository folder.

• The next step is to copy all your deb files (those files that end with .deb) to the repository folder(s). Open Nautilus, navigate to /var/cache/apt/archives and copy all the deb files to the appropriate folder(s). For instance, /home/<username>/repository/disk_1 – keep an eye on the size of the folders. To do it in the terminal:

cp /var/cache/apt/archives/*.deb ~/repository/disk_1

• Remember to replace <username> with your real username.
• If you have many files, it may take quite a while so be patient.

• Change into your repository folder:

cd ~/repository/disk_1/

• Now run the following command to create the Packages.gz file that is needed to for Synaptic to “see” your repository:

sudo dpkg-scanpackages . /dev/null | gzip -9c > Packages.gz

• I suggest you copy and paste this to avoid any typos.
• Please note that every time you add any more .deb files to this folder, you have to create a new Packages.gz file using the above command before the new file(s) will show up in Synaptic (or Aptitude).
• Be sure to install the build-essential package (sudo apt-get install build-essential) before running the above command.

There are several ways of using your newly created repository.

I) Keeping the files on a local hard disk

• Edit your /etc/apt/sources.list file like so:

gksudo gedit /etc/apt/sources.list

• And insert this on a new line (preferably the first):

deb file:/home/<username>/repository/disk_1/ /

• Remember to replace <username> with your real username.
• KDE SC users, replace gksudo gedit with kdesudo kate

• Reload your package index like this:

sudo apt-get update

II) Setting up a repo on your intranet (using a web server)

This method is more useful if you want access to your repo from other machines on your network.

• First, follow method I) above and install the apache web server like so:

sudo apt-get install apache2

• Let’s say the ip address of the web server (and the machine with the debian packages) is  192.168.4.100. We need to tell the apache server on 192.168.4.100 where to find the downloaded files:

sudo ln -s /home/<username>/repository/disk_1/ /var/www/repo

• If you’ve not tinkered with apache’s configuration files, /var/www/ is usually the default virtual host.

• Right, now let’s make sure another machine on the network… say 192.168.4.101, can see the repo on 192.168.4.100. Edit the sources.list file on 192.168.4.101 like so:

gksudo gedit /etc/apt/sources.list

• And insert the following on a new line:

deb http://192.168.4.100/repo/ /

• Update 192.168.4.101’s package index:

sudo aptitude update

• I almost always forget to open up port 80 in my firewall. If you’re like me and only allow connections to port 80 on a per-machine basis, you know what to do when you start getting connection refused errors.

II) Using a CD/DVD as a repository:

• Burn the repository folder onto a CD/DVD
• With the disc loaded in your drive, fire up Synaptic and click through the menus like this:

Edit –> Add CD Rom.

• You will be asked to type in a description for the disc; type in anything, for instance: Offline Repository Disk1.
• Click Ok.

Summary

• Go to /var/cache/apt/archives and copy your debian packages to a folder of your choice, for example, /home/<username>/repository/
• Change into the repository directory

cd ~/repository

• and generate a Packages.gz file like this:

sudo dpkg-scanpackages . /dev/null | gzip -9c > Packages.gz

Make sure build-essential is installed (sudo aptitude install build-essential) before you run the above command.

• Add the following line to your sources.list file (/etc/apt/sources.list)

deb file:/home/<username>/repository/ /

• Remember to replace <username> with your real username

• Reload your package index like this:

sudo apt-get update

I know, I know… APTonCD does most of this in a simple intuitive GUI but it forces you to use a CD/DVD approach. You’ll still have to do some tweaking if you want to use any other method… which reminds me, I need to write an APTonCD post.