The joind.in projects are set up so that the build process runs on pull requests when they are opened, which is great! It means that contributors don't have to wait for one of the maintainers to look at it, only to reject the contribution on something that could be picked up automatically. I've had a few questions about the setup so I thought I'd share how it works.
There are a few moving parts here:
- Projects on GitHub
- Jenkins server already available http://jenkins.joind.in
- GitHub's commit status API to allow hooking of things into the pull request workflow
- The GitHub Pull Request Builder Plugin for Jenkins, it's this that does most of the work.
We have our build tasks described with phing, so we created new Jenkins jobs to wrap the same phing task that we use for building the project but configured to accept the specific commits that were coming in via pull request. When the new pull request gets opened, it immediately shows up something like this:
And when it's good to go:
It's super-helpful to see if a test will fail on our build platform, or if there's a syntax or coding style problem - and it gives immediate, quality-oriented feedback to all our contributors. I'd definitely want to use this again with other teams so I thought I'd mention it here.
Also related: A very useful post that we referred to when setting this up, which you can find at http://blog.kabisa.nl/2013/11/05/building-github-pull-requests-with-jenkins/