Add support for .gitlab-ci.yaml files

[ilovelinux]

Fixes #595

[sirosen]

Thanks for filing the issue and PR! I had been under the impression that GitLab only supports the .yml suffix -- that's what's in their docs, and they do not mention support for .gitlab-ci.yaml.

Can you confirm that GitLab supports the .yaml suffix and will execute pipelines from configs with this extension?

There are a couple of things which need to be tweaked for this to merge:

• CI tests confirm that .yaml is rejected by the regex -- that needs to be updated
• per the comment in the .pre-commit-hooks.yaml file, that hook is autogenerated, so the config which generates it needs to be updated

[andrew-rowson-lseg]

The root gitlab pipeline config can be customised per repo

Personally, I like .gitlab/.gitlab-ci.yaml. The .yml-only restriction I think only applies to pipelines that gitlab loads from external URLs.

[sirosen]

Personally, I like .gitlab/.gitlab-ci.yaml.

Yeah, that makes total sense to me. If I used GitLab more actively, I could see adopting something similar.

If you customize the path at which the file is found, my initial thought is that it makes sense for the check-gitlab-ci pre-commit hook to need to be parametrized extra, e.g.

repos:
  - repo: https://github.com/python-jsonschema/check-jsonschema
    rev: 0.33.0
    hooks:
      # match any YAML files in .gitlab/ ending in '-ci'
      - id: check-gitlab-ci
        files: ^\.gitlab/.*-ci\.(yaml|yml)$

This PR is changing the default rule to match on .gitlab-ci.yaml (in the repo root), which is fine but doesn't seem like it has a strong rationale as the only exceptional case if .gitlab/* is also interesting.

I looked at schemastore, and they have some very permissive globs for gitlab-ci. Perhaps the correct solution is to follow their rule, which is to accept \.gitlab-ci\.(yaml|yml) anywhere in the repo, not just the root.