Reduce size of gitlab-runner-helper images

What does this MR do?

This MR reduces the size of the gitlab-runner-helper images by:

  • Using miniperl instead of perl (required for git-submodule)
  • Using apk --no-cache when installing Alpine packages
REPOSITORY                    TAG                 IMAGE ID            CREATED             SIZE
gitlab/gitlab-runner-helper   arm-7f95086         a6c261cb3c57        5 days ago          135.7 MB
gitlab/gitlab-runner-helper   x86_64-7f95086      150caa5f8496        5 days ago          81.79 MB
gitlab/gitlab-runner-helper   arm-d18f38e         5c70f6e2a381        29 minutes ago      101.7 MB
gitlab/gitlab-runner-helper   x86_64-d18f38e      539912ee8c70        30 minutes ago      40.38 MB
  • The arm image size is reduced by 34MB (25.0%)
  • The x86_64 image size is reduced by 41.4MB (50.6%)

Does this MR meet the acceptance criteria?

  • Documentation created/updated
  • Tests
    • Added for this feature/bug
    • All builds are passing
  • Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?


cc @ayufan @tmaczukin