* Use deep copies in `PrepareForUpdate()`
* Preserve select metadata from new pod
* Use patch to add ephemeral container `kubectl debug`
* Distinguish between pod vs /ephemeralcontainers NotFound
This changes the `/ephemeralcontainers` subresource of `/pods` to use
the `Pod` kind rather than `EphemeralContainers`.
When designing this API initially it seemed preferable to create a new
kind containing only the pod's ephemeral containers, similar to how
binding and scaling work.
It later became clear that this made admission control more difficult
because the controller wouldn't be presented with the entire Pod, so we
updated this to operate on the entire Pod, similar to how `/status`
works.
Automatic merge from submit-queue
replace global registry in apimachinery with global registry in k8s.io/kubernetes
We'd like to remove all globals, but our immediate problem is that a shared registry between k8s.io/kubernetes and k8s.io/client-go doesn't work. Since client-go makes a copy, we can actually keep a global registry with other globals in pkg/api for now.
@kubernetes/sig-api-machinery-misc @lavalamp @smarterclayton @sttts
