- When registering with a 1.17+ API server, MutatingWebhookConfiguration and ValidatingWebhookConfiguration objects can now request that only `v1` AdmissionReview requests be sent to them. Previously, webhooks were required to support receiving `v1beta1` AdmissionReview requests as well for compatibility with API servers <= 1.15.

- Fixed an issue with the `garbagecollection` controller registering duplicate event handlers if discovery requests failed. ([#117992](https://github.com/kubernetes/kubernetes/pull/117992), [@liggitt](https://github.com/liggitt))

  So, if you want to just keep the existing behavior, you can register `ClusterEventWithHint` with no `QueueingHintFn` in it. 

TokenReview](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.13/#tokenreview-v1-authentication-k8s-io) for the new tokens for improved scoping. Under audit logging, the new alpha-level "dynamic audit configuration" adds support for [dynamically registering webhooks to receive a stream of audit events](https://kubernetes.io/docs/tasks/debug/debug-cluster/audit/#webhook-backend). Finally, we've enhanced secrets protection by graduating [etcd encryption](https://kubernetes.io/docs/tasks/administer-c...

* Fix kubectl describe for pods with controllerRef  ([#45467](https://github.com/kubernetes/kubernetes/pull/45467), [@ddysher](https://github.com/ddysher))
* Skip errors when unregistering juju kubernetes-workers ([#48144](https://github.com/kubernetes/kubernetes/pull/48144), [@ktsakalozos](https://github.com/ktsakalozos))