- Deprecate the default service IP CIDR. The previous default was `10.0.0.0/24` which will be removed in 6 months/2 releases. Cluster admins must specify their own desired value, by using `--service-cluster-ip-range` on kube-apiserver. ([#81668](https://git...

* Add `--enable-admission-plugins` `--disable-admission-plugins` flags and deprecate `--admission-control`. When using the separate flag, the order in which they're specified doesn't matter.  ([#58123](https://github.com/kubernetes/kubernetes/pull/58123), [@hzxuzhonghu](https://github.com/hzxuzhonghu))

- Kubeadm: deprecate self-hosting support. The experimental command "kubeadm alpha self-hosting" is now deprecated and will be removed in a future release. ([#95125](https://github.com/kubernetes/kubernetes/pull/95125), [@neolit123](https://github.com/neolit123)) [SIG...

- Kube-proxy: deprecate `--healthz-port` and `--metrics-port` flag, please use `--healthz-bind-address` and `--metrics-bind-address` instead ([#88512](https://github.com/kubernetes/kubernetes/pull/88512), [@SataQiu](https://github.com/SataQiu)) [SIG Network]

- GCERegionalPersistentDisk feature is GA now! ([#70716](https://github.com/kubernetes/kubernetes/pull/70716), [@jingxu97](https://github.com/jingxu97))
- Added secure port 10259 to the kube-scheduler (enabled by default) and deprecate old insecure port 10251. Without further flags self-signed certs are created on startup in memory. ([#69663](https://github.com/kubernetes/kubernetes/pull/69663), [@sttts](https://github.com/sttts))

## Release Notes From SIGs

- Deprecate `--record` flag in `kubectl`. The `--record` flag is being replaced with the [mechanism](https://github.com/kubernetes/enhancements/tree/master/keps/sig-cli/859-kubectl-headers) which annotates HTTP requests with kubectl command details. ([#1028...

 - Remove alpha `CSIMigrationXXComplete` flag and add alpha `InTreePluginXXUnregister` flag. Deprecate `CSIMigrationvSphereComplete` flag and it will be removed in v1.22. ([#98243](https://github.com/kubernetes/kubernetes/pull/98243), [@Jiawei0227](https://github.com/Jiawei0227))

This release does *not* deprecate the v1 HorizontalPodAutoscaler API.

### Generic Ephemeral Volume feature graduates to GA

The generic ephemeral volume feature moved to GA in 1.23.

- Client-go: if resetting the body fails before a retry, an error is now surfaced to the user. ([#109050](https://github.com/kubernetes/kubernetes/pull/109050), [@MadhavJivrajani](https://github.com/MadhavJivrajani))
- Deprecate apiserver_dropped_requests_total metric. The same data can be read from apiserver_request_terminations_total metric. ([#109018](https://github.com/kubernetes/kubernetes/pull/109018), [@wojtek-t](https://github.com/wojtek-t))

* Add a new kubelet endpoint for serving first-class resource metrics ([#73946](https://github.com/kubernetes/kubernetes/pull/73946), [@dashpole](https://github.com/dashpole))
* Deprecate AWS, Azure, GCE and Cinder specific volume limit predicates. ([#74544](https://github.com/kubernetes/kubernetes/pull/74544), [@gnufied](https://github.com/gnufied))