Allow regional GKE clusters instead of just zonal
Problem to solve
We want to require the use of multiple availability zones for production deployments. On the GKE cluster creation UI, you can choose to deploy as 'regional' instead of 'zonal'. This seems unavailable on GitLab when creating a cluster, you can only choose one single zone to deploy to.
Further details
The available scaling settings on GCP change from 'N nodes' to 'N nodes per zone', so the new GitLab settings will need to reflect that
Proposal
Allow selecting a whole region, such as europe-west1.
What does success look like, and how can we measure that?
The cluster creation page should be usable for creating regional clusters.
Links / references
https://cloud.google.com/kubernetes-engine/docs/concepts/regional-clusters