Support Kubernetes PVCs

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?

Fixes gitlab-org/gitlab-ci-multi-runner#2258

Can pvc support subpath property?

@carllhw Could you elaborate? I wonder what you're referring to other that mounting on a subpath. Please note, I myself are quite new to k8s, thats why I don't really understand what feature you're requesting.

@zj https://kubernetes.io/docs/concepts/storage/volumes/#using-subpath

unmarked as a Work In Progress

assigned to @tmaczukin

@zj I left few comments.

assigned to @zj

resolved all discussions

assigned to @tmaczukin

@zj Looks good! :)

After looking on this again two ideas came to my head:

1. We should add support for ConfigMapVolumeSource.Items. Having this the user will be able to select which values from the ConfigMap should be mounted and in which files they should be stored. This is of course an improvement that could be added in the future, but I think it's so easy to implement right now that we should add it.
2. Since Name for ConfigMap, PVC and Secret configuration structures is used as volume name and as a reference to the source we should probably add this to the description, so - for example - description of KupernetesPVC.Name should be changed from The name of the volume to The name of the volume and Persistent Volume Claim that should be used as a source. And the same for KubernetesConfigMap.Name and KubernetesSecret.Name.

Before merging this MR we should also update documentation of Kubernetes executor because at this moment it doesn't describes volumes support at all.

assigned to @zj

We should add support for ConfigMapVolumeSource.Items

@tmaczukin Given I'm leaving for my two weeks of vacation soon, I'd like to cut scope now and ship what we have. I just pushed the docs. Would you be ok with that? If so, I'll create an issue from this comment

assigned to @tmaczukin

resolved all discussions

mentioned in issue #2573 (closed)

resolved all discussions

approved this merge request

merged

mentioned in merge request !625 (merged)