View source for Git-buildpackage

(To be written up once experimentation is done.)

== Steps ==
(extracted from [[#Experiments]] below.)

=== Initially cloning the git repository from Upstream ===
* Clone the repository from upstream if it doesn't already exist in Gerrit, e.g. from git.debian.org:
 $ cd ~/git/debs/
 $ git clone git://git.debian.org/git/pkg-puppet/''repo''.git
* Set git username/email
 $ git config --global user.name "Your Name"
 $ git config --global user.email you@example.com
* Set up the local branches <tt>upstream</tt> and <tt>pristine-tar</tt> from the remote branches (but don't switch to them):
 $ git branch upstream origin/upstream
 $ git branch pristine-tar origin/pristine-tar
* Build a ''source package'':
 $ git-buildpackage --git-export-dir=/var/tmp/build-area/''packagename'' -S
* Build the binary packages with [[Pbuilder]]:
 # pbuilder --basetgz /var/cache/pbuilder/lucid.tgz /var/tmp/build-area/''packagename''/''packagename''_''version''.dsc

=== Making changes and testing snapshot builds ===
* Make changes to the package files
* Make commits or amended commits (uncommitted changes are not exported to the build directory)
* Build snapshot builds for testing with:
 $ git-dch --snapshot
 $ git-buildpackage --git-export-dir=/var/tmp/build-area/''packagename'' -S
 # pbuilder --build --basetgz /var/cache/pbuilder/lucid.tgz /var/tmp/build-area/''packagename''/''packagename''_''version''.dsc

=== Doing a release ===
When a package is ready to be released, use the following steps:
 $ git-dch -R -N ''version''
* Commit the <tt>debian/changelog</tt> file (or amend a previous commit)
* Build the final source package with <tt>--git-tag</tt>:
 $ git-buildpackage --git-tag --git-export-dir=/var/tmp/build-area/varnish -S 
* Build the binaries with Pbuilder as usual

==== Pushing changes into Gerrit ====
Push changes for each of the three branches (if applicable):
$ git push gerrit master:refs/for/master
$ git push gerrit upstream:refs/for/upstream
$ git push gerrit pristine-tar:refs/for/pristine-tar

=== Pushing the repository into Gerrit ===
You should push any repository with local changes into Gerrit.

* Create a new repository, <tt>operations/debs/''packagename''</tt> using the following Gerrit command:
 $ ssh ''username''@gerrit.wikimedia.org -p 29418 'gerrit create-project -d "Package ''packagename''" -n operations/debs/''packagename'' -o ops -p operations/debs'
* Create a new remote called ''gerrit'':
 $ git remote add gerrit ssh://''username''@gerrit.wikimedia.org:29418/operations/debs/''packagename''
* Push the three local branches (''master'', ''upstream'' and ''pristine-tar'') into the fresh remote repository:
 $ git push gerrit --all

== Experiments ==
Mark is experimenting with building puppet using git-buildpackage, in labs.

On i-00000080:

* The debian puppet package git repository was cloned into ~/git/debs/puppet:
 $ cd ~/git/debs/
 $ git clone git://git.debian.org/git/pkg-puppet/puppet.git
* Package build was attempted with <tt>git-buildpackage --git-ignore-new --git-pristine-tar</tt>
* Signing the package failed, as the Debian maintainer's secret key is not available.
* Package build was attempted without signing:
 $ git-buildpackage --git-ignore-new --git-pristine-tar -us -uc
* This worked. We ended up with built packages in ~/git/debs, and a dirty git working dir.
* The git working directory was made clean again, and another build was attempted using
 $ git-buildpackage --git-ignore-new --git-pristine-tar -us -uc --git-export-dir=/var/tmp/build-area/puppet
* This worked as well. Packages were being built, and the git working dir remained clean. Packages ended up in the build dir.
* The debian git dir only had version 2.7.6, but we want 2.7.7rc2. So I tried importing the dev release with
 $ git-import-orig /tmp/puppet-2.7.7rc2.tar.gz
* This failed, as there was no local ''upstream'' branch in the cloned git repository yet. Ok, so let's create it from ''origin/upstream'':
 $ git branch upstream origin/upstream
* Now the import worked. But commits were made, with the default git name/mail address. Do set it:
 $ git config --global user.name "Your Name"
 $ git config --global user.email you@example.com
* Try another build.
 $ git-buildpackage --git-ignore-new --git-pristine-tar -us -uc --git-export-dir=/var/tmp/build-area/puppet
* Oops. This used version 2.7.6. But, the git-buildpackage manual says changing the changelog itself all the time isn't a good idea. Let's try git-dch:
 $ git-dch --snapshot
 Changelog has been prepared for snapshot #1 at 48473567008ad82cdb0d0a5654dffe7c868fad91
<pre>
$ git diff
diff --git a/debian/changelog b/debian/changelog
index 796b61e..f6da810 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+puppet (2.7.6-1ubuntu1~1.gbp484735) UNRELEASED; urgency=low
+
+  ** SNAPSHOT build @48473567008ad82cdb0d0a5654dffe7c868fad91 **
+
+  * Imported Upstream version 2.7.7rc2
+
+ -- Mark Bergsma <mark@i-00000080.pmtpa.wmflabs>  Wed, 23 Nov 2011 14:06:45 +0000
+
</pre> 
* Cool, but not quite what I need. There was no commit, so let's simply revert that, and try again after reading the git-dch manual:
 $ git checkout debian/changelog
 $ git-dch --snapshot -N 2.7.6+2.7.7rc2 --git-author
<pre>
$ git diff
diff --git a/debian/changelog b/debian/changelog
index 796b61e..06a9cac 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+puppet (2.7.6+2.7.7rc2~1.gbp484735) UNRELEASED; urgency=low
+
+  ** SNAPSHOT build @48473567008ad82cdb0d0a5654dffe7c868fad91 **
+
+  * Imported Upstream version 2.7.7rc2
+
+ -- Mark Bergsma <mark@wikimedia.org>  Wed, 23 Nov 2011 14:23:22 +0000
+
</pre>
* Now let's try a new build:
 $ git-buildpackage --git-ignore-new --git-pristine-tar -us -uc --git-export-dir=/var/tmp/build-area/puppet
* Whoops. It built 2.7.6 instead. Probably because it exported HEAD into the build area. Let's see what it does within the git repository.
 $ git-buildpackage --git-ignore-new --git-pristine-tar -us -uc
* So that worked. Hmm, inconsistent. :( I guess we could choose not to care about version numbers for snapshots, and only care about them for releases.

== External links ==
* [http://honk.sigxcpu.org/projects/git-buildpackage/manual-html Git-buildpackage documentation]

[[Category:Ubuntu]] [[Category:Package management]]