ReleaseEngineering/Upgrading Buildbot

Structure

Mozilla's copy of Buildbot is at http://hg.mozilla.org/build/buildbot. There are two branches in this repository - upstream and default. The former is basically a copy of the Buildbot source from git, while the latter is the locally patched version.

If you have a look at the revision graph, you'll see that upstream gets updated with each new buildbot release, then merged into default.

Upgrading Process

Get a copy of upstream Buildbot from a tag, as a tarball. The easiest way is to go to the 'downloads' page on github and download the appropriate tarball. You can also make a clone and use git archive.

In a checkout of build/buildbot,

• switch to the upstream branch,
• rm -rf everything,
• untar the tarball, and
• use hg addremove to process any added or removed files.

Commit with a message like "Imported Buildbot-0.8.2 source", then tag with e.g., BUILDBOT_0_8_2.

Switch to the default branch and use hg merge to merge the changes. Resolve any conflicts (bearing in mind that they may be significant, rather than merely textual).

Commit your updates to default. That's it - now it's time to test!

Staging a New Master

On a staging machine,

• clone your buildbot hg repo into /tmp or somewhere convenient
• create a new virtualenv in /tools, using python-2.6.5:

 /tools/python-2.6.5/bin/virtualenv /tools/buildbot-0.8.2

• activate it

 source /tools/buildbot-0.8.2/bin/activate

• install the buildbot (master) package

 cd master/
 pip install .

Back in your staging directory, edit the Makefile to point it at the new version:

 BUILDBOT=/tools/buildbot-0.8.2/bin/buildbot

that's it - make restart and check the /about URI to make sure it upgraded (you should see an hg revision in the footer). You will probably need to run buildbot upgrade-master to upgrade the database first, but the buildmaster will tell you that.