In bringing back Clayton's PR piece-by-piece this was almost as easy to
implement as his version, and is much more like what I think we should be
doing.
Specifically, any time which defines a .DeepCopy() method will have that method
called preferentially. Otherwise we generate our own functions for
deep-copying. This affected exactly one type - resource.Quantity. In applying
this heuristic, several places in the generated code were simplified.
To achieve this I had to convert types.Type.Methods from a slice to a map,
which seems correct anyway (to do by-name lookups).
Automatic merge from submit-queue
federation: replacing string credentials field by secretRef
Fixes https://github.com/kubernetes/kubernetes/issues/25761
Replaced the string Credentials field in ClusterSpec by secretRef as discussed in https://github.com/kubernetes/kubernetes/issues/25761.
Also updated the clusterController to use this new secretRef field while creating a client to talk to a k8s cluster.
cc @lavalamp @kubernetes/sig-cluster-federation
Automatic merge from submit-queue
Make name validators return string slices
Part of the larger validation PR, broken out for easier review and merge. Builds on previous PRs in the series.
