[Buildbot-devel] AnyBranchScheduler in update mode

[Brian Warner]

"Carl Dionne" <cdionne at quazal.com> writes:

>    I would like to configure BuildBot to automatically perform a quick
>    build, in update mode, for all commits done in any branches.  The
>    AnyBranchScheduler almost does the job, except that since it works by
>    creating new schedulers sharing the same builder, performing a cvs
>    update may involve changing many files by moving from one branch to
>    another one, and will slow down compile.
>
>    Is there a way to achieve this?

The best long-term answer is probably to enhance the slave-side CVS
checkout/update step to be able to cache some number of branches. This
probably involves changing the current use of a 'source' directory to
something like 'source-%s' % branchname. My hunch is that the code changes
are actually pretty minimal, if we don't try to get fancy and delete
infrequently-used branches. Probably in buildbot/slave/commands.py:1115, in
SourceBase.start, something to set self.srcdir specially depending upon the
branch name. (in fact, breaking it out to a function that can be overridden
by each VC subclass would be ideal, since each VC subclass has a different
concept of branchnames anyways).

To bound the space consumed would be a little more effort, but maybe it would
be easier to have an external cron job look for these source-* directories
and periodically delete ones that haven't been modified for, say, a month or
two.

>    I also tried changing the AnyBranchScheduler to create new builders as
>    it creates new schedulers, where these builders would be using a
>    separate build, but I don't know how to let BuildBot know that it
>    should activate or use these new builders, after they have been added
>    to the configuration.

Yeah, creating new Builders from within the Scheduler is pretty hard (any
time you create a new Builder, you pretty much have to reload the whole
config file). It would be easier to have a loop in your master.cfg that
creates all those Builders ahead of time.

good luck,
 -Brian