Skip to content

Framework Jenkins CI

When opening a new Pull Request, an automated tool, Jenkins, takes care of launching a full build. It allows to see directly if your code can be merged without breaking everything. We have a dedicated Jenkins instance running at CERN. Only members of the cp3-llbb CERN e-group can access this page.

As soon as a new Pull Request is opened, or if an already opened Pull Request is updated, an automatic build is launched. Only one build can be executed at the same time: every other builds are queued. A build typically takes about 1 hour.

Once a build is started, the Pull Request status on GitHub is updated. Once done, the status will either be green (the code compiles) or red (something is wrong). You can click on the Details link to access the Jenkins job report and the compilation log. For more information, see https://github.com/blog/1935-see-results-from-all-pull-request-status-checks.

The Pull Request won't be mergeable until the Pull Request status is green.

Bootstrap

Since the build is automatized, Jenkins needs to know how-to setup the CMSSW env by itself. To do that, two files are necessary:

  • CMSSW.release: This file must contains only a string representing the CMSSW version to use to setup the framework. Be careful not to add a line break at the end of the line.
  • CMSSW.arch: The SCRAM_ARCH of the CMSSW release.
  • bootstrap_jenkins.sh: This file is a bash script executed by Jenkins just before building the framework, but after the CMSSW env is setup. You must use this file to install all the dependencies of the framework.
  • jenkins_postbuild.sh: This file is executed by Jenkins after the compilation.

Do not forget to update these files when changes are done to the release or the dependencies, otherwise the build will fail.

Technical details

  • Jenkins instance
  • OpenShift instance: jenkins-cp3-llbb (access is restricted to administrators. If you want / need access, please ask Christophe D. or Sébastien B.). This is the platform hosting our Jenkins instance inside an isolated container (for more information, look for Docker on Google).

A github bot also exists; it's a generic github user, member of the cp3-llbb organization. It needs push authorization to a repository to properly update the PR status. Password for this user can be found on the protected CP3 wiki

Note

Sometimes, the container responsible for the build get stuck in creating phase and you'll need to kill it and retrigger a new build. To do that, connect to the OpenShift instance, and select on the left menu Applications → Pods. Click on the build instance in the list, and on the new page, select Delete in the Actions menu (top right). It may takes some time before the container is killed. If it's still stuck in deleting after a few minutes, you'll have to open a new ticket here.

Troubleshooting

If a build/test fails because of unexpected connection glitch, you can re-trigger jenkins by commenting please test to the pull request