How I Used Basic Debian Packaging with Git

I was recently looking for a way to support building a basic Debian package for email2pdf - a fairly simple Python program I maintain. In particular, I wanted to:

The first bit turned out to be easier than I thought, since it turns out all you really need for a basic Debian package is a control file that looks a bit like this (for the moment, this assumes a version number hardcoded in this file):

Package: my_package_name
Version: 1.0.0
Section: base
Priority: optional
Architecture: all
Depends: some, other, debian-packages
Recommends: yet-another-package
Maintainer: Andrew Ferrier <andrew.ferrier@example.com>
Description: Some short description
 A much longer description that goes on for ages and ages and ages.

Once you have that, you put it in a directory tree called DEBIAN/, together with any files you want to put in the package, and run dpkg-deb --build at the root of it. For example:

mkdir -p DEBIAN/
mkdir -p DEBIAN/usr/bin
cp control/file/above DEBIAN/control
cp some/other/location/myprogram DEBIAN/usr/bin
dpkg-deb --build . .

(You can see a fuller example here in the builddeb_real target here).

However, the second part - to determine an appropriate version string for the Debian package - was fiddlier. Eventually, I settled on a similar technique to the one described here.

However, rather than git describe --tags --long, as recommended in the answer, I instead use git describe --dirty. This has the following advantages:

Once we have a way to determine the version string (git describe --dirty), now we need a way to get this into the Debian package control file. This can be done with a simple sed script:

sed 's/Version: .*/Version: $(GITDESCRIBE)/' debian/DEBIAN/control_template > debian/DEBIAN/control

control_template is basically a template-ized version of control, where the Version field contains a placeholder (see the real version from email2pdf as an example).

Once the above sed command has been executed, the dpkg-deb --build command can be executed as above.