Three categories of jobs run on ci.bazel.io: bootstrap/maintenance, projects, and hidden jobs.
Several jobs control the bootstrap and maintenance of Bazel, they are mostly under the maintenance and bazel folders:
benchmark: job running continously to produce benchmarks of Bazel published at perf.bazel.build.maintenance/install-bazel: job that install Bazel release on all the slaves.maintenance/gerrit-verifier: job to detect pending reviews on Gerrit that need validation (that have been marked as Presubmit-Ready).bazel/nightly: job that handles the global tests, it runs every night.bazel/release: copy of bazel/nightly that runs for the release, it also handle publishing the release artifacts.bazel/presubmit: copy of bazel/nightly that is triggered when someone set Presubmit-Ready+2 on Gerrit.All the other jobs are defined by the bazel_github_job template that simply run Bazel on a github repository. The templates are in jenkins/*.tpl and the definitions in jenkins/jobs/BUILD and jenkins/jobs/jobs.bzl.
The JOBS definition in jenkins/jobs/jobs.bzl is the list of jobs actually running on ci.bazel.io. On the staging, to make the full build faster, we use the STAGING_JOBS definition, which is a strip down version of the JOBS definition.
PR/_project_ is a copy of the job for project that validates a GitHub pull request on project with the latest release of Bazel.CR/_project_ is the same as PR-_project_ but for validating Gerrit review request.Global/_project_ is another copy of the job but for use by the global presubmit test.