Jenkins is a pluggable continuous integration system. The Google team is running a Jenkins server on a private GCE instance for the Kubernetes project in order to run longer integration tests, continuously, on different providers. Currently, we are running tests on GCE, GKE, and AWS.

The flow of the Google Jenkins server:

• Under the kubernetes-build job: Every 2 minutes, Jenkins polls for a batch of new commits, after which it runs the build.sh script (in this directory) on the latest tip. This results in build assets getting pushed to GCS and the latest.txt file in the ci bucket being updated.
• On trigger, and every half hour (which effectively means all the time, unless we're failing cluster creation), e2e variants run, on the latest build assets in GCS:
  • kubernetes-e2e-gce: Standard GCE e2e.
  • kubernetes-e2e-gke: GKE provider e2e, with head k8s client and GKE creating clusters at its default version.
  • kubernetes-e2e-gke-ci: GKE provider e2e, with head k8s client and GKE creating clusters at the head k8s version.
  • kubernetes-e2e-aws: AWS provider e2e.
• Each job will not run concurrently with itself, so, for instance, Jenkins executor will only ever run one kubernetes-build job. However, it may run the jobs in parallel, i.e. kubernetes-build may be run at the same time as kubernetes-e2e-gce. For this reason, you may see your changes pushed to our GCS bucket rapidly, but they may take some time to fully work through Jenkins. Or you may get lucky and catch the train in 5 minutes.
• There are many jobs not listed here, including upgrade tests, soak tests, and tests for previous releases.

The scripts in this directory are directly used by Jenkins, either by curl from githubusercontent (if we don't have a git checkout handy) or by executing it from the git checkout. Since Jenkins is an entity outside this repository, it's tricky to keep documentation for it up to date quickly. However, the scripts themselves attempt to provide color for the configuration(s) that each script runs in.

New jobs should be specified as YAML files to be processed by Jenkins Job Builder. The YAML files live in job-configs and its subfolders. Jenkins runs Jenkins Job Builder in a Docker container defined in job-builder-image, and triggers it using update-jobs.sh. Jenkins Job Builder uses a config file called jenkins_jobs.ini which contains the location and credentials of the Jenkins server.