Developer/Fedora
Introduction
OLPC maintains a variant of the Fedora Linux distribution. Many developers, over the course of their careers developing for the XO, develop a need to package software for the XO, either because they wish to fix a bug in software contained in an existing package or because they wish to contribute new software (other than activities) to the system. This document is intended to explain how to package bug fixes for OLPC system software that is maintained in Fedora. Other documents, such as [1] discuss the less common case of adding entirely new pieces of software to Fedora and of adding new activities, which are not currently maintained in Fedora.
There are two broad kinds of work that must be done to be able to take responsibility for maintaining an OLPC fork of a Fedora package - requesting authority to maintain a Fedora package and learning how to maintain a Fedora package. Fortunately, these tasks can be performed in parallel.
Terminology
- upstream authors
- are people who release source code for consumption by package maintainers and who accept or reject patches from interested individuals
- package maintainers
- are people who accept source code releases from upstream authors and who combine that source code with packaging instructions in order to produce packaged software
- package maintainers are also responsible for contributing patches to upstream authors that fix bugs or that make the upstream software inter-operate more smoothly with other software
- Frequently in OLPC, package maintainers and upstream authors are the same person.
- source releases
- are typically tarballs of source code that have been permanently published at a fixed URL, along with validation data such as MD5sums or the author's public key and a digital signature.
- (it's important for many reasons that source code be permanently accessible for all packages. Please make sure that yours is.)
- packaging instructions
- consist of a '.spec' file and zero or more patches to a source release.
- packaged source code
- is the 'source object' of a software distribution much as '.c' and '.h' files are the units of source code for building C binary objects.
- packaged software
- is the 'binary object' of a software distribution much as '.o' files are the binary objects linked together to produce C binaries
Outside Reading
Here is a collection of sites that I have found useful in learning to maintain Fedora packages for OLPC:
Fedora Procedures
- https://fedoraproject.org/wiki/PackageMaintainers/UpdatingPackageHowTo - How to update packages maintained in Fedora
- https://fedoraproject.org/wiki/PackageMaintainers/UsingCvsFaq - How to access source code for packages maintained in Fedora
- http://fedoraproject.org/wiki/PackageMaintainers/UsingKoji - How to build RPMs with Fedora's build infrastructure
- http://fedoraproject.org/wiki/Packaging/ReviewGuidelines - Checklist that must be met to add a new package to Fedora
RPM Hints
- http://fedoranews.org/alex/tutorial/rpm/ Walk-through of common RPM-related tasks
Making or Modifying RPMS
- http://docs.fedoraproject.org/drafts/rpm-guide-en/ch-creating-rpms.html - Draft reference material on how to create RPMs
- http://rpm.org/max-rpm-snapshot/ - Out of date reference material on how to create RPMS
- http://fedoraproject.org/wiki/Docs/Drafts/BuildingPackagesGuide - Recent but incomplete walk-through of how to create Fedora packages
Fedora Infrastructure
- https://admin.fedoraproject.org/pkgdb/ - Website for managing authorization to update Fedora packages
- http://koji.fedoraproject.org/koji/ - Status website for the Fedora build system
Requesting Authority to Help Maintain an Existing Package or Branch of a Package
First and most important - if you get confused, ask for help! (Then help improve this page!)
Next, let's assume that you've demonstrated the interest and ability required to help to maintain an OLPC branch of a Fedora package. I'll use the OLPC branch of xkeyboard-config as a running example. Then, you might:
- Request a RedHat Bugzilla account
- RedHat and Fedora use Bugzilla extensively to keep track of administrative tasks relating to package maintenance.
- Request a Fedora account
- Just follow the 'Get a Fedora Account' instructions to access the Fedora Account System (FAS2).
- Request membership in the fedorabugs and cvsextras groups through FAS2.
- Just follow these instructions
- Ask a Fedora Package Maintainer (such as dgilmore) to sponsor you.
- Use your Fedora account to request authority to update the OLPC branch of the package you want to fix.
- Login to Fedora Package Database
- Navigate to the page for your package, e.g. the dist-olpc2 branch of xkeyboard-config
- Request ACL entries to update the OLPC branch of the package you want to fix.
Learning How to Maintain a Package
- Request an account on teach.laptop.org, install Fedora yourself, or install appropriate packages (rpmbuild, rpmdevtools, mock, and koji) if your distribution offers recent versions;
- Anonymously check out your package from Fedora CVS
CVSROOT=:pserver:anonymous@cvs.fedoraproject.org:/cvs/pkgs
cvs co <module>
- Use mock or rpmbuild to learn how to build your package
cd <module>/OLPC-2
make mockbuild MOCKCFG=fedora-7-i386
- [Politely] Seek help from OLPC and Fedora developers as you discover confusions.
Placing a Package into a Build Stream
Once you've managed to modify your chosen package and to produce mock-built RPMs which satisfy you, then it's time to make your modifications available to the wider OLPC world. To do this, you need to insert your packages into an OLPC buildstream, either by (recommended) building and tagging them in Fedora's Koji package maintenance system or (cheap-skates) by placing them in an appropriate dropbox on dev.laptop.org. The exact tags or stream-names you should use will vary over time and depending on the specific nature of your work. Ask on OLPC's development IRC channels for the most up-to-date information. After you have completed one of these steps, then your package can be included in an OLPC build. Depending on the exact build stream you're working in, this may occur automatically or you may be required to negotiate with your build stream's maintainer.