Add CI features to GitLab API

Currently the GitLab API is lacking almost all CI features.

We are unable to:

• update the project CI settings - !2303 (merged)
• list/create/update/delete variables - !2264 (merged)
• list/create/delete triggers - !2286 (merged)
• list/update/delete runners (nice to have) - !2640 (merged)
• list/update/delete shared runners (nice to have) - !2640 (merged)
• list commits with CI data - !2261
• extend details of single commit to include CI data - !2261
• list recent builds (running, finished or all) - !2207 (merged)
• cancel or retry builds - !2207 (merged)

The task is to implement or reimplement this in context of GitLab API. Some of the mentioned features were already implemented in GitLab CI API.

How we should do it?

• Decide how the new API endpoints would look like (@ayufan can help with that).
• (Re-)Implement this by reusing code from https://gitlab.com/gitlab-org/gitlab-ce/tree/8-2-stable/lib/ci/api.
• Add tests (@ayufan can help with that).

Reassigned to @tmaczukin

Milestone changed to 8.4

mentioned in issue #4263 (closed)

And this one: https://gitlab.com/gitlab-org/gitlab-ce/issues/4255 of which I will take care probably.

We had a call yesterday with @ayufan and we've decided to:

1. Implement API for all per-project CI features.
2. Don't implement API for global CI features. They are less needed - we can work on them in 8.4 release if there will be time or move them to one of future releases.
3. Leave old GItLab CI API as it is - for runners and for backward compatibility. If there is need to reimplement some feature in GitLab API we should move the logic to a seperate class/service and reuse it in both APIs.

mentioned in merge request !2207 (merged)

mentioned in merge request !2261

mentioned in merge request !2264 (merged)

Added ~19173 label

mentioned in merge request !2286 (merged)

mentioned in merge request !2303 (merged)

mentioned in issue #3001 (closed)

mentioned in commit 9664424c

Marked the task update the project CI settings - !2303 (merged) as completed

mentioned in commit f981da44

Marked the task list/create/update/delete variables - !2264 (merged) as completed

mentioned in commit ba42b033

mentioned in commit 2a89073c

mentioned in commit dd6c69e6

mentioned in commit 948bb655

Marked the task list/create/delete triggers - !2286 (merged) as completed

Marked the task cancel or retry builds - !2207 (merged) as completed

Marked the task list recent builds (running, finished or all) - !2207 (merged) as completed

mentioned in commit c7ee7eea

mentioned in merge request !2640 (merged)

Milestone changed to 8.5

mentioned in commit 1817b766

mentioned in commit 778da502

Marked the task list/update/delete runners (nice to have) - !2640 (merged) as completed

Milestone changed to 8.7

mentioned in issue #13915 (closed)

Assignee removed

I don't have any immediate ideas what else we are missing in GitLab API for CI.

I'm closing that for now.

Status changed to closed

Mentioned in commit maxraab/gitlab-ce@c7ee7eea

Mentioned in commit maxraab/gitlab-ce@2a89073c

Mentioned in commit maxraab/gitlab-ce@778da502

mentioned in merge request !14785