* Set an upper bound (5 minutes) on how long the Kubelet will wait before exiting when the client cert from disk is missing or invalid. This prevents the Kubelet from waiting forever without attempting to bootstrap a new client credentials. ([#59316](https://github.com/kubernetes/kubernetes/pull/59316), [@smarterclayton](https://github.com/smarterclayton))

*   The admission webhook configurations API, part of the admissionregistration API, is now at v1beta1. Delete any existing webhook configurations before you upgrade, and update your configuration files to use the latest API. For this and the previous...

  - NetworkPolicy resources will no longer be served from `extensions/v1beta1` in v1.16. Migrate use to the `networking.k8s.io/v1` API, available since v1.8. Existing persisted data can be retrieved via the `networking.k8s.io/v1` API.

EndpointSlices with Pod referencing Nodes that don't exist couldn't be created or updated. The behavior on the EndpointSlice controller has been modified to update the EndpointSlice without the Pods that reference non-existing Nodes and keep retrying until all Pods reference existing Nodes. However, if `service.Spec.PublishNotReadyAddresses` is set, all the Pods are published without retrying. Fixed EndpointSlices metrics to reflect correctly the number of desired EndpointSlices when no endpoints...

  - NetworkPolicy resources will no longer be served from `extensions/v1beta1` in v1.16. Migrate use to the `networking.k8s.io/v1` API, available since v1.8. Existing persisted data can be retrieved via the `networking.k8s.io/v1` API.

* Updating apiserver to return UID of the deleted resource. Clients can use this UID to verify that the resource was deleted or waiting for finalizers. ([#45600](https://github.com/kubernetes/kubernetes/pull/45600), [@nikhiljindal](https:/...

The Cluster API effort is currently undergoing a complete rehaul of the existing codebase, moving off Terraform and into using govmomi directly.

### SIG-windows

SIG Windows focused on stability and reliability of our existing feature set. We primarily fixed bugs as we march towards a near future stable release.

## Action Required

- Reverted a kubectl azure auth module change where oidc claim spn: prefix was omitted resulting a breaking behavior with existing Azure AD OIDC enabled api-server ([#87507](https://github.com/kubernetes/kubernetes/pull/87507), [@weinong](https://github.com/weinong)) [SIG API Machinery, Auth and Cloud Provider]

empty cgroupDriver value in the KubeletConfiguration is now always set to "systemd" unless the user is explicit about it. This requires existing machine setups to configure the container runtime to use the "systemd" driver. Documentation on this topic can be found here: https://kubernetes.io/docs/setup/production-environment/container-runtimes/. When upgrading existing clusters / nodes using "kubeadm upgrade" the old cgroupDriver value is preserved, but in 1.22 this change will also apply to "upgrade"....

* Add --no-negcache flag to kube-dns to prevent caching of NXDOMAIN responses. ([#66036](https://github.com/kubernetes/kubernetes/pull/66036), [@prameshj](https://github.com/prameshj))
* fix data loss issue if using existing azure disk with partitions in disk mount  ([#63270](https://github.com/kubernetes/kubernetes/pull/63270), [@andyzhangx](https://github.com/andyzhangx))