Tag Archives: equivs

How and Why to Create Ubuntu Metapackages

Yesterday I wrote about my plans to make deploying new Ubuntu servers both easier and more repeatable by relying on apt metapackages.

I’ve been working on the implementation, and it’s going pretty well so far.  This documents the basic steps:

First, I installed the equivs package

aptitude install equivs

At this point, I’m not including any config files or post installation tasks, so I only have to worry about the control file.

#equivs-control my-metapackage

This generates a control file template in the current directory that you edit. I want to make sure my system has ufw, munin-node, logrotate, rsync, mlocate and wget installed, and I cleaned out the options I didn’t need, so my control file looks like this:

### Commented entries have reasonable defaults.
### Uncomment to edit them.
Section: misc
Priority: optional
Standards-Version: 3.6.2

Package: my-metapackage
Version: 0.01
Maintainer: Your Humble Scribe <fake@fake.com>
Depends: ufw, munin-node, logrotate, rsync, mlocate, wget
Description: Depends on Useful Bits and Pieces
 This is a dependency package that we use to make sure that basics,
 like a firewall, rsync, munin-node, etc, are installed.

Next step is to turn that into a debian package:

#equivs-build my-metapackage
dh_clean -k
dpkg-deb: building package `my-metapackage' in `../my-metapackage_0.01_all.deb'.
The package has been created.
Attention, the package has been created in the current directory,
not in ".." as indicated by the message above!

Now to test it out:

sudo dpkg -i my-metapackage_0.01_all.deb

This will install my-metapackage, but that’s not enough. Dpkg can’t satisfy remote dependancies, so it will throw errors for each of the dependencies you created and leave your newly installed package in a broken state. You can then use aptitude to resolve these missing dependencies to complete the process:

sudo aptitude -fy --safe-resolver install

This tells aptitude to install to fix any missing dependencies. 

That should be it.  I’ll note though, that for some reason, aptitude was insisting on removing my packages, rather than fixing the broken dependencies.  I’m not sure why, and I’m not sure why its working now