Run all jobs on a gitlab ci MR pipeline, even if some don't have a merge_request_event rule, but do not run both MR and branch pipelines - gitlab

Question

In case the terminology is not standard, here is how I am using the below terms:
branch pipeline: A pipeline that is run when pushing to a branch.
MR pipeline: A pipeline that is run on a merge request, or pushes to a merge request branch.
I want to write a pipeline with two jobs, job_A and job_B. job_A should run on all pipelines. job_B should run only on merge request pipelines. One solution is to combine the workaround proposed in issue 194129, adding a workflow rule of - if: $CI with a merge_request_event rule, i.e.:
image: alpine
workflow:
rules:
- if: $CI
stages:
- stage_A
- stage_B
job_A:
stage: stage_A
script:
- echo "Hello from Job A"
job_B:
stage: stage_B
rules:
- if: $CI_PIPELINE_SOURCE == 'merge_request_event'
script:
- echo "Hello from Job B"
Now my pipeline runs in full on the MR -- which is what I wanted. However, two pipelines are being run now, the branch pipeline and the MR pipeline.
I want both job_A and job_B to run on MR pipelines even though job_A doesn't have the merge_request_event rule. But, I only want one pipeline to run when an MR is open -- the MR pipeline. How can I achieve this?

Answer 1

The correct answer is found in the gitlab docs.
workflow:
rules:
- if: $CI_PIPELINE_SOURCE == "merge_request_event"
- if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS
when: never
- if: $CI_COMMIT_BRANCH

Answer 2

Try using only:variables. I had the same issue when mixing only/except with rules in one pipeline.
job_B:
stage: stage_B
only:
variables:
- $CI_PIPELINE_SOURCE == "merge_request_event"
script:
- echo "Hello from Job B"