continuous integration - How to run gitlab stage periodically?

Question

How can I run a gitlab stage periodically? I am aware of pipeline schedules documented here: https://docs.gitlab.com/ee/ci/pipelines/schedules.html. I am only interested in running a particular test stage of a branch. The issue is the branch I want to target has a lot of other stages involved with it. One option might be introducing a variable in the script portion that says if true then execute the script. However, this can be cumbersome and require a lot of changes to all the stages of the ci file for that particular branch under consideration.

question from:https://stackoverflow.com/questions/65910754/how-to-run-gitlab-stage-periodically

Answer 1

You can control when your jobs run using the only/except keywords, or the more advanced rules keyword along with the pipeline source variable.

Example with only:

scheduled_test:
  stage: tests
  image: my_image:latest
  only:
    - schedules
  script:
    - ./run_some_things.sh

The only keyword lets you define some conditions that mean "this job only runs if these conditions are true", and offers a shorthand to check the source of the pipeline. schedules means that the pipeline was started from a schedule rather than a push, trigger, etc. The except keyword is just the opposite. If it had except: schedules the job would always run except if it was scheduled. You can see the full documentation for the only/except keywords here: https://docs.gitlab.com/ee/ci/yaml/#onlyexcept-basic

As of Gitlab version 12.3, the rules keyword extends the possibilities of the only/except options. We could get the same result from the example above like this:

scheduled_test:
  stage: tests
  image: my_image:latest
  rules:
    - if: '$CI_PIPELINE_SOURCE == "schedule"'
      when: always
    - if: '$CI_PIPELINE_SOURCE == "push"'
      when: never

In this example, we check the predefined variable $CI_PIPELINE_SOURCE to see what started this pipeline. If it's "schedule", we always run this job. As an example, if the source is "push" (so the pipeline was started by a git push command), this job will never run. With the rules keyword, all if statements are OR'ed together, so the example above reads, if the source is schedule, always run OR if the source is a push, never run. However, you can AND multiple conditionals together in the same if:

rules:
  - if: '$CI_PIPELINE_SOURCE == "push" && $MY_CUSTOM_VARIABLE == true'
    when: manual

You can read the full documentation for the rules keyword here: https://docs.gitlab.com/ee/ci/yaml/#rules