### SIG Node

SIG-Node advanced several features and made incremental improvements in a few key topic areas this release.

- Added apiserver identity to the following metrics: 

      - `apiserver_storage_transformation_latencies_microseconds ` -> `apiserver_storage_transformation_duration_seconds`
      - `apiserver_storage_data_key_generation_latencies_microseconds` -> `apiserver_storage_data_key_generation_duration_seconds`
      - `apiserver_request_count` -> `apiserver_request_total`
      - `apiserver_request_latencies_summary`

- The API server now re-uses data encryption keys while the kms v2 plugin key ID is stable.  Data encryption keys are still randomly generated on server start but an atomic counter is used to prevent nonce collisions. ([#116155](https://github.com/kubernetes/kubernetes/pull/116155), [@enj](https://github.com/enj))

* The `kube-cloud-controller-manager` flag `--service-account-private-key-file` was non-functional and is now deprecated. ([#50289](https://github.com/kubernetes/kubernetes/pull/50289), [@liggitt](https://github.com/liggitt))
    * The `kube-cloud-controller-manager` flag `--use-service-account-credentials` is now honored consistently, regardless of whether `--service-account-private-key-file` was specified.

* kubectl create secret has a new option --from-env-file that populates a secret from file which follows a key=val format for each line.

- Kubeadm: during execution of the `certs check-expiration` command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA....

- kube-controller-manager
  - The deprecated `--insecure-experimental-approve-all-kubelet-csrs-for-group` flag has been removed.
- kubelet
  - The deprecated `--google-json-key` flag has been removed. Remove the `--google-json-key` flag from kubelet invocations before upgrading. ([#69354](https://github.com/kubernetes/kubernetes/pull/69354), [@yujuhong](https://github.com/yujuhong))

  * You can remove the "old" taints (stored internally as annotations) at any time after the upgrade by doing `kubectl annotate nodes <node name> scheduler.alpha.kubernetes.io/taints-` (note the minus at the end, which means "delete the taint with this key")

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the...