How to enable RBAC for clusters created during pre-RBAC era
Type of issue
Problem to solve
There must be a migration path for those who had created the cluster before RBAC support was introduced with Legacy Authorisation turned on.
People willing to upgrade their clusters should have an official howto with all possible drawbacks covered. For some creating a new cluster is not an option.
At the moment all we see is the disabled unchecked checkbox inside Operations -> Kubernetes -> Kubernetes cluster details
without any explanation what to do to enable it.
Actually, it's not clear whether it's possible to enable RBAC on already configured clusters or not.
Probably this could be covered here: https://docs.gitlab.com/ee/user/project/clusters/#