### CSI Health Monitoring

The CSI health monitoring feature is being released as a second Alpha in Kubernetes 1.21. This feature enables CSI Drivers to share abnormal volume conditions from the underlying storage systems with Kubernetes so that they can be reported as events on PVCs or Pods. This feature serves as a stepping stone towards programmatic detection and resolution of individual volume health issues by Kubernetes.

* Requests with the query parameter `?watch=` are treated by the API server as a request to watch, but authorization and metrics were not correctly identifying those as watch requests, instead grouping them as list calls. ([#48583](https://github.com/kubernetes/kubernetes/pull/48583), [@smarterclayton](https://github.com/smarterclayton))

// makes that struct also non-comparable, and generally doesn't add
// any size (as long as it's first).
type http2incomparable [0]func()

// synctestGroupInterface is the methods of synctestGroup used by Server and Transport.
// It's defined as an interface here to let us keep synctestGroup entirely test-only
// and not a part of non-test builds.

- Fixes a 1.30.0 regression in openapi descriptions of imagePullSecrets and hostAliases fields to mark the fields used as keys in those lists as either defaulted or required. ([#124694](https://github.com/kubernetes/kubernetes/pull/124694),...

      endpoint now gets broken when that endpoint becomes non-ready
      (rather than continuing until the endpoint is fully deleted).
  
    - Traffic to a service IP now starts getting rejected (as opposed to
      merely dropped) as soon as there are no longer any *usable*
      endpoints, rather than waiting until all of the terminating
      endpoints have terminated even when those terminating endpoints
      were not being used.
  

volumes to be specified directly in the pod specification for ephemeral use cases. They can be used to inject arbitrary states, such as configuration, secrets, identity, variables or similar information, directly inside pods using a mounted volume. This was initially introduced in 1.15 as an alpha feature, and it moved to GA. This feature is used by some CSI drivers such as the [secret-store CSI driver](https://github.com/kubernetes-sigs/secrets-store-csi-driver).

### Promoted CRD Validation...

### SIG CLI

- The feature gate was mentioned as `csiMigrationRBD` where it should have been `CSIMigrationRBD` to be in parity with other migration plugins. This release correct the same and keep it as `CSIMigrationRBD`.
  

		// inline marks.
		for p := s.pp.Text; p != nil; p = p.Link {
			if p.As == obj.ANOP || p.As == obj.AFUNCDATA || p.As == obj.APCDATA || p.As == obj.ATEXT ||
				p.As == obj.APCALIGN || p.As == obj.APCALIGNMAX || Arch.LinkArch.Family == sys.Wasm {
				// Don't use 0-sized instructions as inline marks, because we need
				// to identify inline mark instructions by pc offset.

- Enable external plugins can be used as subcommands for kubectl create command if subcommand does not exist as builtin only when KUBECTL_ENABLE_CMD_SHADOW environment variable is exported. ([#116293](https://github.com/kubernetes/kubernetes/pull/116293), [@ardaguclu](https://github.com/ardaguclu))