- The plugin mechanism functionality now closely follows the git plugin design ([#66876](https://github.com/kubernetes/kubernetes/pull/66876), [@juanvallejo](https://github.com/juanvallejo))

- Support for Windows Server 2019 for worker nodes and containers
- Support for out of tree networking with Azure-CNI, OVN-Kubernetes and Flannel
- Improved support for pods, service types, workload controllers and metrics/quotas to closely match the capabilities offered for Linux containers

A <code>nil</code> channel is never ready for communication.
</p>

<p>
A channel may be closed with the built-in function
<a href="#Close"><code>close</code></a>.
The multi-valued assignment form of the
<a href="#Receive_operator">receive operator</a>
reports whether a received value was sent before
the channel was closed.
</p>

<p>
A single channel may be used in

- `DelayingQueue.ShutDown()` can now be invoked multiple times without causing a closed channel panic. ([#77170](https://github.com/kubernetes/kubernetes/pull/77170), [@smarterclayton](https://github.com/smarterclayton))

- Apiserver add a new flag --goaway-chance which is the fraction of requests that will be closed gracefully(GOAWAY) to prevent HTTP/2 clients from getting stuck on a single apiserver. 
  After the connection closed(received GOAWAY), the client's other in-flight requests won't be affected, and the client will reconnect. 

* fix azure disk storage account init issue ([#55927](https://github.com/kubernetes/kubernetes/pull/55927), [@andyzhangx](https://github.com/andyzhangx))
* Allow code-generator tags in the 2nd closest comment block and directly above a statement. ([#55233](https://github.com/kubernetes/kubernetes/pull/55233), [@sttts](https://github.com/sttts))

- Fixes regression in logging spurious stack traces when proxied connections are closed by the backend ([#82588](https://github.com/kubernetes/kubernetes/pull/82588), [@liggitt](https://github.com/liggitt))

pkg io, func NopCloser(Reader) ReadCloser
pkg io, func ReadAll(Reader) ([]uint8, error)
pkg io, type ReadSeekCloser interface { Close, Read, Seek }
pkg io, type ReadSeekCloser interface, Close() error
pkg io, type ReadSeekCloser interface, Read([]uint8) (int, error)
pkg io, type ReadSeekCloser interface, Seek(int64, int) (int64, error)
pkg io, var Discard Writer

* GCE: provide an option to disable docker's live-restore on COS/ubuntu ([#55260](https://github.com/kubernetes/kubernetes/pull/55260), [@yujuhong](https://github.com/yujuhong))
* Fix kube-proxy hang due to panic when requesting a closed healthcheck. ([#46450](https://github.com/kubernetes/kubernetes/pull/46450), [@MrHohn](https://github.com/MrHohn))

SubjectAccessReview API in the `authorization.k8s.io` API group now allows providing the user uid. ([#49677](https://github.com/kubernetes/kubernetes/pull/49677), [@dims](https://github.com/dims))

* After a kubelet rotates its client cert, it now closes its connections to the API server to force a handshake using the new cert. Previously, the kubelet could keep its existing connection open, even if the cert used for that connection was expired and rejected by the API server. ([#49899](https://gi...