"content": {
                                    "application/json": {
                                        "schema": {
                                            "$ref": "#/components/schemas/HTTPValidationError"
                                        }
                                    }
                                },
                            },

    - [Cluster Autoscaler](#cluster-autoscaler)
    - [Deployment](#deployment)
    - [Federation](#federation)
    - [Internal Storage Layer](#internal-storage-layer)
    - [Node Components](#node-components)
    - [kubectl](#kubectl)
    - [RBAC](#rbac)
    - [Scheduling](#scheduling)
    - [Service](#service)
    - [StatefulSet](#statefulset)
    - [Volumes](#volumes)

- kubeadm: all master components are now exclusively relying on the `PriorityClassName` pod spec for annotating them as cluster critical components. Since `scheduler.alpha.kubernetes.io/critical-pod` annotation is no longer supported by Kubernetes 1.14 this annotation is no longer added to master components. ([#73857](https://github.com/kubernetes/kubernetes/pull/73857), [@ereslibre](https://github.com/ereslibre))...

This API provided status of etcd, kube-scheduler, and kube-controller-manager components, but only worked when those components were local to the API server, and when kube-scheduler and kube-controller-manager exposed unsecured health endpoints. Instead of this API, etcd health is included in the kube-apiserver health check and kube-scheduler/kube-controller-manager health checks can be made directly against those components' health endpoints. ([#93570](https://github.com/kubernetes/kubernetes/pull/93570),...

  It is possible that this will cause problems with some third-party components
  that improperly depended on those rules. If this affects you, you can run
  `kubelet` with `--feature-gates=IPTablesOwnershipCleanup=false`, but a bug should also be filed against the third-party component. ([#114472](https://github.com/kubernetes/kubernetes/pull/114472), [@danwinship](https://github.com/danwinship))

### Deploy a more secure control plane with kubeadm

restarts. If the extended resource is exported by a device plugin, its capacity will change to a valid value after the device plugin re-connects with the Kubelet. If the extended resource is exported by an external component through direct node status capacity patching, the component should repatch the field after kubelet becomes ready again. During the time gap, pods previously assigned with such resources may fail kubelet admission but their controller should create new pods in response to such...

flag --port=0 to kube-controller-manager and kube-scheduler manifests to disable insecure serving. Without this flag the components by default serve (e.g. /metrics) insecurely on the default node interface (controlled by --address). Users that wish to override this behavior and enable insecure serving can pass a custom --port=X via kubeadm's "extraArgs" mechanic for these components. ([#92720](https://github.com/kubernetes/kubernetes/pull/92720), [@neolit123](https://github.com/neolit123)) [SIG Cluster...

### Cluster Lifecycle

- kubeadm: consider --bind-address or --advertise-address and --secure-port for control plane components when the feature gate WaitForAllControlPlaneComponents is enabled. Use /livez for kube-apiserver and kube-scheduler, but continue using /healthz for kube-controller-manager until it supports /livez. ([#128474](https://github.com/kubernetes/kube...