gitlabgitlab-ci

Dynamic CI/CD variables not working in rules:changes:compare_to

I have a Gitlab pipeline and I want certain jobs to only run if certain files have changes from the previous commit. Here's my code:

.gitlab-ci.yml

include:
  - local: .ci/container-images.yml
    rules:
      - changes:
          paths:
            - "ansible/**/*"
            - "docker/**/*"
          compare_to: $CI_DEFAULT_BRANCH

.ci/container-images.yml

"build-docker-$[[ inputs.image ]]":
  rules:
    - changes:
        paths:
          - $[[ inputs.context ]]/**/*
        compare_to: $CI_COMMIT_BEFORE_SHA

First I get this error for .gitlab-ci.yml:

include:rules:changes:compare_to is not a valid ref

Then if I set compare_to: main in .gitlab-ci.yml, I get this error from .ci/container-images.yml:

Failed to parse rule for build-docker-ansible-builder: rules:changes:compare_to is not a valid ref

I've tried manually entering a branch name & commit SHA and it works of course.

I'm confused about how these variables work, because according to this:

CI/CD variables are supported.

But then according to this:

Predefined variables made available by the runner cannot be used with trigger jobs or these keywords:

So can I use the variables or not? I would find it very surprising that it's not possible to dynamically specify which ref to compare?

If variables are not allowed, is there another way to accomplish this?

Solution

  • Yes while surprising it does not currently support expansion of variables at the compare_to key. There's a tracking issue here.

    It's been fixed and rolled out already, but judging from the comments seems like it won't come out until version 17.2 gets released