### Documentation

- `kubectl debug` will now print a warning message when using the `--target` option since many container runtimes do not support this yet. ([#101074](https://github.com/kubernetes/kubernetes/pull/101074), [@verb](https://github.com/verb)) [SIG CLI]

### Bug or Regression

rather than booleans. This change to the alpha API is not backwards compatible; implementations of the CRI such as containerd, will need to update to the new API version. ([#58973](https://github.com/kubernetes/kubernetes/pull/58973), [@verb](https://github.com/verb))

* The default Flexvolume plugin directory for COS images on GCE has changed to `/home/kubernetes/flexvolume`, rather than `/etc/srv/kubernetes/kubelet-plugins/volume/exec`. Existing Flexvolume installations in clusters using...

- The underlying format of the `CPUManager` state file has changed. Upgrades should be seamless, but any third-party tools that rely on reading the previous format need to be updated. ([#84462](https://github.com/kub...

- `kubectl debug` gains support for changing container images when copying a pod for debugging, similar to how `kubectl set image` works. See `kubectl help debug` for more information. ([#96058](https://github.com/kubernetes/kubernetes/pull/96058), [@verb](https://github.com/verb)) [SIG CLI]

### Documentation

- The PodShareProcessNamespace feature to configure PID namespace sharing within a pod has been promoted to beta. ([#66507](https://github.com/kubernetes/kubernetes/pull/66507), [@verb](https://github.com/verb))

## API Changes

processes in other containers in a pod, but it also means that the `kubectl exec {pod} kill 1` pattern will cause the Pod to be restarted rather than a single container. ([#45236](https://github.com/kubernetes/kubernetes/pull/45236), [@verb](https://github.com/verb))

  * A new field hostAliases has been added to the pod spec to support [adding entries to a Pod's /etc/hosts file](https://kubernetes.io/docs/concepts/services-networking/add-entries-to-pod-etc-hosts-with-host-aliases/). ...

- Pod process namespace sharing is now Generally Available. The `PodShareProcessNamespace` feature gate is now deprecated and will be removed in Kubernetes 1.19. ([#84356](https://github.com/kubernetes/kubernetes/pull/84356), [@verb](https://github.com/verb))
- Fix handling tombstones in pod-disruption-budged controller. ([#83951](https://github.com/kubernetes/kubernetes/pull/83951), [@zouyee](https://github.com/zouyee))

- Ephemeral containers graduated to beta and are now available by default. ([#105405](https://github.com/kubernetes/kubernetes/pull/105405), [@verb](https://github.com/verb))

* Adds a metric apiserver_request_error_total to kube-apiserver. This metric tallies the number of request_errors encountered by verb, group, version, resource, subresource, scope, component, and code. ([#84780](https://github.com/kubernetes/kubernetes/pull/84780), [@RainbowMango](https://github.com/RainbowMango))

### Feature

- Added KMS `v2alpha1` API. ([#110201](https://github.com/kubernetes/kubernetes/pull/110201), [@aramase](https://github.com/aramase))