A pragmatic guide to creating a simple Debian package.
This HowTo is intended to show that Debian packaging is not that hard. Since Debian packaging is not that hard, why shouldn't plain beginners understand and do it, too?
As a teaser, here's a short list of some reasons to package a program:
- Obviously, you'll need a package if you want the program to be included in Debian.
- The packaging system takes care of the old version, so if a file is moved in the source, uninstall still works properly (unlike when you use make uninstall with the new Makefile)
- A package is an easy format to move programs between computers.
Why does this page even exist?
Since the Debian Policy and the Debian New Maintainers' Guide sometimes are too big to read for people who prefer a more pragmatic approach to problems, this HowTo will focus on a pragmatic approach to learning how to create Debian packages.
The Debian package management chapter of the Debian Reference contains lots of useful information for handling all kinds of problems one runs into with apt and dpkg.
Creating the package
If you want to create an official debian package, make sure it's not already packaged. If somebody is working on the package, you should contact them if you intend to make an official package together. More info is in the New Maintainer's Guide.
Before starting there are some risks you should be aware of:
running make on a system can be a security risk! It is recommended to check beforehand that the Makefile does not contain any funny stuff. Obscure/specially crafted applications might fall into this case.
do NOT run make install, unless you are absolutely sure is safe to do that (check the install target of the makefile). This is a security risk and you may risk to break and/or compromize your system.
- Try to compile the package, but do not install it.
- most compile failures will be the result of missing dependencies (usually they are mostly missing *-dev packages)
- note every new package which you needed to install for compilation
- some of the packages that were already installed on your system might be necessary, too (note: objdump -p | grep NEEDED will show exactly the needed libraries)
- these packages will end up in the build-dependency list of the package
- note quirks and tricks needed for the package to compile (missing files, file modifications, etc.), you will need to reproduce later in the package build rules
- If you think you need specific software not already packaged, make sure that:
- the needed software is not present in another package
the package is not being worked on (ITP (Intent To Package) is pending)
are you sure it's not packaged? You could check other debian based distributions, too.
It is best to create a chroot jail in which to build the application. This mitigates security and system corruption problems. In addition it ensures that any local changes to your machine will not interfere with the build.
If the package compiles, then it means you may have figured out all the dependencies. Don't worry, this will be checked later in a chroot environment. Try the application in a chroot environment (some things might be needed in the chroot jail - for example, proc may need to be mounted, sys to be mounted, etc.). Broken installation scripts are, unfortunately, very common and you probably don't want to run a test installation yet. You might prefer doing the tests in a qemu virtual machine in snapshot mode - changes are not permanent in snapshot mode and you can keep you development machine safe from malitious/broken makefiles.
After the first compilation, it's time to create the Debian specific part of the package.
File debian/control: Add to the Build-Depends (sometimes even Build-Depends-Indep) the list of packages needed to be installed for the application to compile (remember the list done previously). You should leave out any packages that are listed in /usr/share/build-essential/essential-packages-list or /usr/share/build-essential/list and also leave out any packages that listed as dependencies by any of those packages. More detailed information cane be found on the page about control file creation for the new package.
File debian/rules: If any quirking was done then:
- automate the quirking and the changes needed to be done in the debian/rules file under a patch target
- make sure there will be an unpatch target that reverses all the changes done in the patch target
- make the clean target depend on the unpatch target
- make the build target depend on the patch target
Review each of the template files (debian/*.ex). If your package needs that feature, then customize the file as needed and rename it without the ".ex".
Delete all the unneeded templates. Don't worry, they can be restored at any time with "dh_make -a".
Make sure that all the directories you will place files in are listed in the debian/dirs file without a leading slash (/).
Make sure that the files are installed in the proper place (under a directory, not on the root system). Take care at the install target from the application makefile. If the application uses autoconf and automake, it may be enough to set the environment variable DESTDIR, e.g. "make DESTDIR=$(CURDIR)/debian/packagename". (dh_make will set this up automatically.)
Note: very often the upstream package will install files under /usr/local. DO NOT INSTALL ANY FILES IN THERE.
Initial compilation of the package
TODO: add notes
All tests in chroot
Why is it a good idea to use a chroot?
- No risk to break the developer's system
- Wrongly installed packages can be identified easily (ls -lR in the root of the chroot before and after the build; diff -u before.list after.list)
Missing build dependecies are identified easier, thus avoiding serious FTBFS (Fails To Build From Source) bugs
- The chroot system is a pure Debian system belonging to one suite only (e.g., Sarge, Etch or Sid if the chroot was built properly with debootstrap or cdebootstrap)
Testing the package
licensecheck -r *
TODO: add notes
Test all the packages with lintian.
Test all the .deb packages with piuparts.
Check points for any package
- Is there a man page for every executable file in the package? In some rare cases it makes sense to have one man page for multiple binaries in a package.
- Does it have a Debian menu entry? (daemons usually don't need this) Does it have a .desktop file?
If there are architecture independent things in the package and if they are big enough, are those packaged in a seperate package with arch all?
Does the package compile cleanly? This does not mean that you should redirect the errors to /dev/null
- Does lintian scream when checking the .changes file?
- What does piuparts have to say about the .debs?
This page is still incomplete; please help by adding information to it. Do not forget that the information here should be in a concise form.
- The Oolite package was created following this techinque (actually, this page was written during oolite's initial packaging stage)
a somewhat simplistic example which assumes no upstream source when starting the package, can be found at Creating a new package from scratch - this is more useful to upstream developers, not to people doing pure packaging work.
Advanced Packaging Procedures
RPM - Converting a .RPM into .DEB - generally leads to bad results
Creating package without some particular architectures - for easy porting
External useful links
http://www.debian.org/doc/manuals/apt-howto/ and package apt-howto