Provide detailed error for removed apiVersions

[lblackstone]

Proposed changes

Before creating any resource, check if the requested apiVersion
has been deprecated/removed on the targeted version of k8s,
and print a detailed error message if so. This should avoid
confusion from users who try to use unsupported versions.

Related issues (optional)

[lblackstone]

I'm still in the process of unifying the ServerVersion usage, but this draft shows the expected output when a user tries to create an unsupported apiVersion of a resource on k8s 1.16.

This is now RFR

[metral]

Overall LGTM.

Is there a reason in the OP image that we're both warning && error'ing with the same message?

I'd imagine they'd be mutually exclusive, as a warning is a heads-up with no action required but is suggested, and an error is a true failure. As presented, I'd expect to only see an error that I'd have to fix because I'm using an unsupported group/version.

Thoughts?

[lblackstone]

Is there a reason in the OP image that we're both warning && error'ing with the same message?

No, not a good reason. I'll make it mutually exclusive.

[lblackstone]

Here's what it looks like after the update on a 1.16 cluster.

[metral]

Looks great.

nit: Can we link to the official k8s API docs as part of the message so that users can check them out if necessary?

e.g. https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.16

[lblackstone]

Updated with docs link: