Add prometheus support to gitlab-ce

[simontesar]

The integrated prometheus in Gitlab does currently not work with an RBAC enabled cluster and is also not considered in the charts service template.

This fixes #1191

[k8s-ci-robot]

Hi @simt2. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with @k8s-bot ok to test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[simontesar]

Note: I actually signed the CLA and am still not sure why it shows up as not signed.

[kfox1111]

Can gitlab-ce use an external prometheus? There already is a prometheus chart and it might be easier to maintain then if it was reused?

[viglesiasce]

Yes I agree with @kfox1111 that this should make a conditional dependency on the Prometheus chart and be able to point to an existing chart.

Please update with those changes.

[viglesiasce]

Should allow a configurable Prometheus URL and also allow deploying the prometheus chart rather than deploying its own Prometheus.

[mgoodness]

Linking this to the discussion underway in #1138

[mgoodness]

Closing this because it increasingly looks like we're going to deprecate our GitLab charts and point users to the "official" ones. I encourage you to submit this work there.