* Websocket requests may now authenticate to the API server by passing a bearer token in a websocket subprotocol of the form `base64url.bearer.authorization.k8s.io.<base64url-encoded-bearer-token>`. ([#47740](https://github.com/kubernetes/kubernetes/pull/47740), [@liggitt](https://github.com/liggitt))

- The helping message of commands which have sub-commands is now clearer and more instructive. It will show the full command instead of `kubectl <command> --help ...`
  

count](https://github.com/kubernetes/enhancements/issues/554) feature was also moved to beta. This enables a volume plugin to specify the maximum number of a given volume type per node as a function of the node characteristics (for example, a larger limit for larger nodes, a smaller limit for smaller nodes).

SIG Storage also worked on a number of [Container Storage Interface (CSI) features](https://github.com/kubernetes/enhancements/issues/178) this quarter in anticipation of moving support...

* Fixes v1.17.0 regression in --service-cluster-ip-range handling with IPv4 ranges larger than 65536 IP addresses ([#86534](https://github.com/kubernetes/kubernetes/pull/86534), [@liggitt](https://github.com/liggitt))

- Fixes v1.17.0 regression in --service-cluster-ip-range handling with IPv4 ranges larger than 65536 IP addresses ([#86534](https://github.com/kubernetes/kubernetes/pull/86534), [@liggitt](https://github.com/liggitt)) [SIG Network]

- `kubeadm`: promoted feature gate `EtcdLearnerMode` to `beta`. Learner mode for
  joining `etcd` members is now enabled by default. ([#120228](https://github.com/kubernetes/kubernetes/pull/120228), [@pacoxu](https://github.com/pacoxu))

- Kubeadm: added the experimental (alpha) feature gate `EtcdLearnerMode` that allows etcd members to be joined as learner and only then promoted as voting members ([#113318](https://github.com/kubernetes/kubernetes/pull/113318), [@pacoxu](https://github.com/pacoxu))

* Use separate client for leader election in scheduler to avoid starving leader election by regular scheduler operations. ([#53793](https://github.com/kubernetes/kubernetes/pull/53793), [@wojtek-t](https://github.com/wojtek-t))

* kube-apiserver: a request body of a CREATE/UPDATE/PATCH/DELETE resource operation larger than 100 MB will return a 413 "request entity too large" error. ([#73805](https://github.com/kubernetes/kubernetes/pull/73805), [@caesarxuchao](https://github.com/caesarxuchao))

- Client-go: Optimized leaders renewing leases by updating leader lock optimistically without getting the record from the API server first. Also, a new metric `leader_election_slowpath_total` was added to allow users to monitor how many leader elections are updated non-optimistically.