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.
Maintainers of FlexVolume drivers should implement a CSI driver and move users of FlexVolume to CSI.
Users of FlexVolume should move their workloads to CSI driver.

### Deprecation of klog specific flags

- Fix race in alpha aggregated discovery handler
  Yes, discovery document will correctly return the resources for aggregated apiservers that do not implement aggregated disovery ([#115805](https://github.com/kubernetes/kubernetes/pull/115805), [@alexzielenski](https://github.com/alexzielenski)) [SIG API Machinery]

- Kube-proxy: added `--logging-format` flag to support structured logging. ([#117800](https://github.com/kubernetes/kubernetes/pull/117800), [@cyclinder](https://github.com/cyclinder))
- NodeVolumeLimits implement the `PreFilter` extension point for skipping the Filter phase if the Pod doesn't use volumes with limits. ([#115398](https://github.com/kubernetes/kubernetes/pull/115398), [@tangwz](https://github.com/tangwz)) [SIG Scheduling]

* Rename `--cgroups-per-qos` to `--experimental-cgroups-per-qos` in Kubelet ([#36767](https://github.com/kubernetes/kubernetes/pull/36767), [@vishh](https://github.com/vishh))
* Implement CanMount() for gfsMounter for linux ([#36686](https://github.com/kubernetes/kubernetes/pull/36686), [@rkouj](https://github.com/rkouj))

- The kubelet and the default docker runtime now support running ephemeral containers in the Linux process namespace of a target container. Other container runtimes must implement support for this feature before it will be available for that runtime. ([#84731](https://github.com/kubernetes/kubernetes/pull/84731), [@verb](https://github.com/verb)) [SIG Node]

  
    The comment references an issue with `pure = select(...)` which appears
    to be resolved considering this now builds.
  
  - make kube::util::find-binary not dependent on bazel-out/ structure
  
    Implement an aspect that outputs go_build_mode metadata for go binaries,

- A customizable `OrderedScoreFuncs()` function was introduced. Out-of-tree plugins 
  that used the scheduler's preemption interface could implement this function
  for custom preemption preferences or return nil to keep the current behavior. ([#121867](https://github.com/kubernetes/kubernetes/pull/121867), [@lianghao208](https://github.com/lianghao208))

- Implement a queueing hint for PersistentVolumeClaim/Add event in CSILimit plugin. ([#124703](https://github.com/kubernetes/kubernetes/pull/124703), [@utam0k](https://github.com/utam0k)) [SIG Scheduling and Storage]

- Autoscaling/v2beta2 and custom_metrics/v1beta2 have been introduced, which implement metric selectors for Object and Pods metrics, as well as allowing AverageValue targets on Objects, similar to External metrics. ([#64097](https://github.com/kubernetes/kubernetes/pull/64097), [@damemi](https://github.com/damemi)) Courtesy of SIG...

* fix the create azure file pvc failure if there is no storage account in current resource group ([#56557](https://github.com/kubernetes/kubernetes/pull/56557), [@andyzhangx](https://github.com/andyzhangx))

* Implement envelope service with gRPC, so that KMS providers can be pulled out from API server. ([#55684](https://github.com/kubernetes/kubernetes/pull/55684), [@wu-qiang](https://github.com/wu-qiang))