* Caching added to the OIDC client auth plugin to fix races and reduce the time kubectl commands using this plugin take by several seconds. ([#38167](https://github.com/kubernetes/kubernetes/pull/38167), [@ericchiang](https://github.com/ericchiang))

which can enable or disable pod preemption.

### Storage Plugin Migration

There is work under way to [migrate the internals of in-tree storage plugins](https://github.com/kubernetes/enhancements/issues/625) to call out to CSI Plugins,
while maintaining the original API.
The [Azure Disk](https://github.com/kubernetes/enhancements/issues/1490)

- Kubelet plugin registration now has retry and exponential backoff logic for when registration of plugins (such as CSI or device plugin) fail. ([#73891](https://github.com/kubernetes/kubernetes/pull/73891), [@taragu](https://github.com/taragu))

or GA.
  * New Flex Volume Plugin enables users to use out-of-process volume plugins that
are installed to “/usr/libexec/kubernetes/kubelet-plugins/volume/exec/” on
every node, instead of being compiled into the Kubernetes binary. See [example](examples/volumes/flexvolume/README.md) for details.
  * vendor volumes into a pod. It expects vendor drivers are installed in the

- Fixed a regression since 1.24 in the scheduling framework when overriding MultiPoint plugins (e.g. default plugins).

    temporary workaround.
      * The standard `bridge` plugin have been validated to interoperate with
         the new CRI + CNI code path.
      * If you are using plugins other than `bridge`, make sure you have
        updated custom plugins to the latest version that is compatible.
* **CNI plugins now affect node readiness**
  * Kubelet will now block node readiness until a CNI configuration file is

- `kubelet_runtime_operations_errors` -> `kubelet_runtime_operations_errors_total`
- `kubelet_device_plugin_registration_count` -> `kubelet_device_plugin_registration_total`
- `kubelet_device_plugin_alloc_latency_microseconds` -> `kubelet_device_plugin_alloc_duration_seconds`
- `docker_operations` -> `docker_operations_total`
- `docker_operations_latency_microseconds` -> `docker_operations_latency_seconds`

* Added support to a hierarchy of kubectl plugins (a tree of plugins as children of other plugins). ([#45981](https://github.com/kubernetes/kubernetes/pull/45981), [@fabianofranz](https://github.com/fabianofranz))
    * Added exported env vars to kubectl plugins so that plugin developers have access to global flags, namespace, the plugin descriptor and the full path to the caller binary.

- '`kubelet_kubelet_credential_provider_plugin_duration` was renamed to `kubelet_credential_provider_plugin_duration`
  and `kubelet_kubelet_credential_provider_plugin_errors` was renamed to `kubelet_credential_provider_plugin_errors`.'
   ([#113754](https://github.com/kubernetes/kubernetes/pull/113754), [@logicalhan](https://github.com/logicalhan))

  - [stable] New volume plugin for the Quobyte Distributed File System ([docs](http://kubernetes.io/docs/user-guide/volumes/#quobyte)) ([kubernetes/features#80](https://github.com/kubernetes/enhancements/issues/80))