`UnversionedKubeletConfigMap` feature gate to Beta and enabled the feature by default. This implies that 1) for new clusters kubeadm will start using the `kube-system/kubelet-config` naming scheme for the kubelet ConfigMap and RBAC rules, instead of the legacy `kubelet-config-x.yy` naming. 2) during upgrade, kubeadm will only write the new scheme ConfigMap and RBAC objects. To disable the feature you can pass `UnversionedKubeletConfigMap: false` in the kubeadm config for new clusters. For upgrade on existing clusters...

                        },
                        "400": {"description": "Client error level 0"},
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

  // "Host" in httpHeaders instead.
  // +optional
  optional string host = 3;

  // Scheme to use for connecting to the host.
  // Defaults to HTTP.
  // +optional
  optional string scheme = 4;

  // Custom headers to set in the request. HTTP allows repeated headers.
  // +optional
  repeated HTTPHeader httpHeaders = 5;
}

  <mime-type type="text/x-scala">
    <_comment>Scala source code</_comment>
    <glob pattern="*.scala"/>
    <sub-class-of type="text/plain"/>
  </mime-type>

  <mime-type type="text/x-scheme">
    <_comment>Scheme source code</_comment>
    <glob pattern="*.scm"/>
    <sub-class-of type="text/plain"/>
  </mime-type>

  <mime-type type="text/x-sed">
    <_comment>Sed code</_comment>

    * Upgrade OpenAPI 3.1.0, this uses JSON Schema 2020-12.
    * Upgrade Swagger UI to version 5.x.x, that supports OpenAPI 3.1.0.

### API-Machinery

* Fixed webhooks to use the scheme provided in clientConfig, instead of defaulting to http. ([#60943](https://github.com/kubernetes/kubernetes/pull/60943), [@jennybuckley](https://github.com/jennybuckley))

- 'Container `preStop` and `postStart` lifecycle handlers using `httpGet` now
  honor the specified `scheme` and `headers` fields. This enables setting custom
  headers and changing the scheme to `HTTPS`, consistent with container
  startup/readiness/liveness probe capabilities. Lifecycle handlers configured
  with `scheme: HTTPS` that encounter errors indicating the endpoint is actually

beta and enabled by default. CustomResourceDefinitions with [structural schemas](https://github.com/kubernetes/enhancements/blob/master/keps/sig-api-machinery/20190425-structural-openapi.md) now publish schemas in the OpenAPI document served at `/openapi/v2`. CustomResourceDefinitions with non-structural schemas have a `NonStructuralSchema` condition added with details about what needs to be corrected in the validation schema. ([#77825](https://github.com/kubernetes/kubernetes/pull/77825), [@royc...

* kube-apiserver: The `AdmissionConfiguration` type accepted by `--admission-control-config-file` has been promoted to `apiserver.config.k8s.io/v1` with no schema changes. ([#85098](https://github.com/kubernetes/kubernetes/pull/85098), [@liggitt](https://github.com/liggitt))...

  - The `/swaggerapi/*` schema docs, deprecated since 1.7, have been removed in favor of the /openapi/v2 schema docs. ([#72924](https://github.com/kubernetes/kubernetes/pull/72924), [@liggitt](https://github.com/liggitt))