Fixing Double Ci Runs When Pushing to Gitlab Branches

A while back I realized, that every time I pushed some commits to a branch on GitLab two separate CI pipelines started. That soon took up lots of free CI-minutes and became a problem. After some research I found out that this is, while it’s to be expected due to the design of the system, avoidable with a specific configuration addition.

The reason for the double run is, that CI pipelines run for several events in a repository, the two here are push events to a branch and push events to an existing merge request.

The solution sounds as logical as you would expect: just™ tell the pipeline the following:

• if this CI run event is for a branch push and no merge request exists, then run it
• if this CI run event is for a branch push and a merge request exists, then don’t run it
• if this CI run event is for a merge request push then run it

or in GitLab’s CI YAML format:

1WorkflowName:
2  rules:
3    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
4    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS
5      when: never
6    - if: $CI_COMMIT_BRANCH

or with an existing rule:

1WorkflowName:
2  rules:
3    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS && $CI_PIPELINE_SOURCE == "push"
4      when: never
5    - if: $YOUR_OWN_RULES               # add your own rule here

While it looks complicated it’s an addition to my existing workflow that is easy to handle. And it saves CI minutes.