T2 [10]struct{ f T2 }     // T2 contains T2 as component of a struct
	T3 [10]T4                 // T3 contains T3 as component of a struct in T4
	T4 struct{ f T3 }         // T4 contains T4 as component of array T3 in a struct
)

// valid array types
type (
	T5 [10]*T5                // T5 contains T5 as component of a pointer
	T6 [10]func() T6          // T6 contains T6 as component of a function type

    String JOB_TEMPLATE_TITLE_DATA = "job.template.title.data";

    /** The key of the configuration. e.g. return container.getComponent("crawlJob").logLevel("info").webConfigIds([{0}] as String[]).fileConfigIds([{1}] as String[]).dataConfigIds([{2}] as String[]).jobExecutor(executor).execute(); */
    String JOB_TEMPLATE_SCRIPT = "job.template.script";

    /** The key of the configuration. e.g. 0 */

* kubectl port-forward now allows using resource name (e.g., deployment/www) to select a matching pod, as well as the use of --pod-running-timeout to wait until at least one pod is running. ([#59705](https://github.com/kubernetes/kubernetes/pull/59705), [@phsiao](https://github.com/phsiao))

// treat an empty object as if it has an unknown value.
message ClaimSource {
  // ResourceClaimName is the name of a ResourceClaim object in the same
  // namespace as this pod.
  optional string resourceClaimName = 1;

  // ResourceClaimTemplateName is the name of a ResourceClaimTemplate
  // object in the same namespace as this pod.
  //

Cluster Lifecycle

SIG Cluster Lifecycle has been focusing on improving kubeadm in order to bring it to GA in a future release, as well as developing the [Cluster API](https://github.com/kubernetes/kube-deploy/tree/master/cluster-api). For kubeadm, most new features, such as support for CoreDNS, IPv6 and Dynamic Kubelet Configuration, have gone in as alpha features. We expect to graduate these features to beta and beyond in the next release. The initial Cluster API spec and GCE sample implementation...

### 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.

#### New Deprecations

* As a reminder, etcd2 as a backend is deprecated and support will be removed in Kubernetes 1.13. Please ensure that your clusters are upgraded to etcd3 as soon as possible.

## Known Issues

- Concurrently joining control-plane nodes does not work as expected in kubeadm 1.15.0. The feature was planned for release in 1.15.0, but a fix may  come in a follow up patch release.

- 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))

  * Caveat: The alpha version no longer supports, and...