- The in-tree...

  as it requires installation of AzureFile CSI Driver. Users should enable CSIMigration and
  CSIMigrationAzureFile features and install the [AzureFile CSI Driver](https://github.com/kubernetes-sigs/azurefile-csi-driver)
  to avoid disruption to existing Pod and PVC objects at that time. Azure File CSI driver does not support using same persistent

feature gate is enabled, user should not upgrade to Kubernetes v1.22. vSphere CSI Driver does not support Kubernetes v1.22 yet because it uses v1beta1 CRD APIs. Support for v1.22 will be added at a later release. Check the following document for supported Kubernetes releases for a given [vSphere CSI Driver version](https://vsphere-csi-driver.sigs.k8s.io/compatiblity_matrix.html#compatibility-matrix-for-vsphere-csi-driver).

### Workloads that saturate nodes with pods may see pods that fail...

- This release enables in-tree RBD migration to CSI driver with a couple of feature gates.  These featuregates are alpha in this release.

  - `CSIMigrationRBD`: when enabled, it will redirect traffic from in tree rbd plugin ( kubernetes.io/rbd )  to CSI driver ( rbd.csi.ceph.com) , default to `false` now.
  - `IntreePluginRBDUnregister`: Disables the RBD in-tree driver

  The feature gates can be enabled by:

### Failing Test

- DRA driver helper: Fixed handling of apiserver restart when running on a Kubernetes version which did not support the `resource.k8s.io` version used by the DRA driver. ([#133076](https://github.com/kubernetes/kubernetes/pull/133076), [@pohly](https://github.com/pohly)) [SIG Node and Testing]

  If you are using docker manifests there are not visible changes. ([#80266](https://github.com/kubernetes/kubernetes/pull/80266), [@javier-b-perez](https://github.com/javier-b-perez))
- kubeadm now deletes the bootstrap-kubelet.conf file after TLS bootstrap

* Kubernetes 1.12 also enables [Kubelet device plugin registration](https://github.com/kubernetes/enhancements/issues/595) feature by default. Before upgrading to 1.12, ensure the `driver-registrar` CSI sidecar container for your CSI driver is configured to handle plugin registration (set the `--kubel...

Fixed kubelet so it would no longer crash when a DRA(Dynamic Resource Allocation) driver returns a nil as part of the Node(Un)PrepareResources response instead of an empty struct (Did not affect drivers written in Go, first showed up with a driver written in Rust). returns a nil as part of the Node(Un)PrepareResources response instead of an empty struct (did not affect drivers written in Go, first showed up with a driver written in Rust). ([#124091](https://github.com/kubernetes/kubernetes/pull/124091),...

## Known Issues

- Promote CSIMigrationOpenStack to Beta (off by default since it requires installation of the OpenStack Cinder CSI Driver. The in-tree AWS OpenStack Cinder driver "kubernetes.io/cinder" was deprecated in 1.16 and will be removed in 1.20. Users should enable CSIMigration + CSIMigrationOpenStack features and install the OpenStack Cinder CSI Driver (https://github.com/kubernetes/cloud-provider-openstack) to avoid disruption to existing Pod and PVC objects at that time. Users should...