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 */

// 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.
  //

	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

* 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))

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.

[@kow3ns](https://github.com/kow3ns)).

* ControllerRevision type has been added for StatefulSet and DaemonSet history. Clients should not depend on the stability of this type as it may change, as necessary, in future releases to support StatefulSet and DaemonSet update and rollback. We enable this type as we do with beta features, because StatefulSet update and DaemonSet update are enabled. ([#45867](https://github.com/kubernetes/kubernetes/pull/45867), [@kow3ns](https://github.com/kow3ns))...

    * setting `KUBE_PROXY_DAEMONSET=true` in kube-up will now set a `node.kubernetes.io/kube-proxy-ds-ready=true` label on new nodes. In v1.16, the kube-proxy daemonset add-on will switch to using that label as a node selector.
    * In 1.16, the masq-agent daemonset add-on will switch to using `node.kubernetes.io/masq-agent-ds-ready` as a node selector.

- 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))

- SourcesReady provides the readiness of kubelet configuration sources such as apiserver update readiness. ([#81344](https://github.com/kubernetes/kubernetes/pull/81344), [@zouyee](https://github.com/zouyee))