Update the Deployments' API types, defaulting code, conversions, helpers
and validation to use ReplicaSets instead of ReplicationControllers and
LabelSelector instead of map[string]string for selectors.
Also update the Deployment controller, registry, kubectl subcommands,
client listers package and e2e tests to use ReplicaSets and
LabelSelector for Deployments.
This commit adds support for using kubectl scale to scale deployments. Makes use of the
deployments/scale endpoint instead of updating deployment.spec.replicas directly.
This commit introduces a validator for use with Scale updates.
The validator checks that we have > 0 replica count, as well
as the normal ObjectMeta checks (some of which have to be
faked since they don't exist on the Scale object).
