For more information, see [#53288](https://issue.k8s.io/53288).

## Changelog since v1.22.0

## What's New (Major Themes)

### Deprecation of FlexVolume

FlexVolume is deprecated. Out-of-tree CSI driver is the recommended way to write volume drivers in Kubernetes.
See [this doc](https://github.com/kubernetes/community/blob/master/sig-storage/volume-plugin-faq.md#kubernetes-volume-plugin-faq-for-storage-vendors) for more information.

`kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets` annotation is used by a service account (this annotation is not added by default), and Pods are using...

## Urgent Upgrade Notes

  - Clients should reload the token from disk periodically (once per minute is recommended) to ensure they continue to use a valid token. `k8s.io/client-go` version v11.0.0+ and v0.15.0+ reload tokens automatically.

- The formerly publicly-available cAdvisor web UI that the kubelet started using `--cadvisor-port` has been entirely removed in 1.12. The recommended way to run cAdvisor if you still need it, is via a DaemonSet. ([#65707](https://github.com/kubernetes/kubernetes/pull/65707), [@dims](https://github.com/dims))

-...

`kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets` annotation is used by a service account (this annotation is not added by default), and Pods are using...

  After the connection closed(received GOAWAY), the client's other in-flight requests won't be affected, and the client will reconnect. 
  The flag min value is 0 (off), max is .02 (1/50 requests); .001 (1/1000) is a recommended starting point.

## Known Issues