Building Pull Requests (from Stash) on Bamboo

Daniel Sobral

I want to build pull requests (that is, the branch which is being requested to be merged) when they are created on Bamboo. The repository is Stash, so the pull requests would come from personal forks to a known project/repository. I can't find any way to configure such a build from Bamboo, nor trigger it from Stash.

Daniel Sobral

There's presently no way of doing that without writing all the pieces yourself.

On Bamboo, you'll need the following configurations:

* Adding a shell script step to fetch the remote pull request references; they are considered internal use only, but that's the only way right now. More information in this question. I use the following:

git remote | grep -q origin || git remote add origin "https://${bamboo.user}:${bamboo.password}@${bamboo.repo.url}"
git fetch origin '+refs/pull-requests/*/merge-clean:refs/remotes/origin/pr/*'
git fetch origin '+refs/pull-requests/*/from:refs/remotes/origin/pr-from/*'

* Checkout the desired pull request; that means adding a plan variable that can be used on the build tasks. For example, a variable "prnumber" would be used like this:

git checkout pr/${bamboo.prnumber}

* Update build status on Stash using the REST API. This article has everything that's needed, but note that "merge-clean" is what is going to be merged (and, thus, what one needs to build), but the build status on the pull request status on Stash only shows up for the source commit -- that's why I bring the two references above.

* Since there's no variable in Bamboo to indicate whether a build has succeeded or not, I use three steps: mark a build in progress after checkout, mark a build as succeeded as the last task, and then, on a final task (which is always run, whether the previous tasks succeed or not), I mark the build as failed if I don't find a file left behind indicating the build has succeeded (I use a file I create to store the json I send to Stash).

On the Stash side, things are more difficult because you have to listen to pull request events -- the existing hooks don't cover it. This question covers most of what's needed. Because you are not using the hook mechanism, you won't have access to the easy per-repository configuration it provides, so you'll have to write it yourself.

One last note: you use the "queue" REST interface on Bamboo to trigger the build from Stash. Look at your Bamboo's version API documentation here to see the details (a generic REST description found elsewhere doesn't go into that).