- The cloud config for Azure cloud provider can now be initialized from Kubernetes secret azure-cloud-provider in kube-system namespace
    - the secret is a serialized version of `azure.json` file with key cloud-config. And the secret name is azure-cloud-provider.

## Changes since v1.3.0-alpha.4

### Action Required

* Add direct serializer ([#26251](https://github.com/kubernetes/kubernetes/pull/26251), [@caesarxuchao](https://github.com/caesarxuchao))

  // Defaulted to nil.
  // +optional
  optional bool immutable = 5;

  // Data contains the secret data. Each key must consist of alphanumeric
  // characters, '-', '_' or '.'. The serialized form of the secret data is a
  // base64 encoded string, representing the arbitrary (possibly non-string)
  // data value here. Described in https://tools.ietf.org/html/rfc4648#section-4
  // +optional

	wg.Add(2)
	go publish(ReportMetrics(GlobalContext, c.metricsGroups))
	go publish(globalNotificationSys.GetClusterMetrics(GlobalContext))
	wg.Wait()
}

// ReportMetrics reports serialized metrics to the channel passed for the metrics generated.
func ReportMetrics(ctx context.Context, metricsGroups []*MetricsGroupV2) <-chan MetricV2 {
	ch := make(chan MetricV2)
	go func() {
		defer xioutil.SafeClose(ch)

- Fixed a bug in the TopologyManager. Previously, the TopologyManager would only guarantee alignment if container creation was serialized in some way. Alignment is now guaranteed under all scenarios of container creation. ([#87759](https://github.com/kubernetes/kubernetes/pull/87759), [@klueska](https://github.com/klueska)) [SIG Node]

- Restartable init containers resource in pod autoscaler are now calculated. ([#120001](https://github.com/kubernetes/kubernetes/pull/120001), [@qingwave](https://github.com/qingwave))
- Sidecar termination is now serialized and each sidecar container will receive a `SIGTERM` after all main containers and later starting sidecar containers have terminated. ([#120620](https://github.com/kubernetes/kubernetes/pull/120620), [@tzneal](https://github.com/tzneal))

- Ipvs: only attempt setting of sysctlconnreuse on supported kernels ([#88541](https://github.com/kubernetes/kubernetes/pull/88541), [@cmluciano](https://github.com/cmluciano)) [SIG Network]
- Jsonpath support in kubectl / client-go serializes complex types (maps / slices / structs) as json instead of Go-syntax. ([#89660](https://github.com/kubernetes/kubernetes/pull/89660), [@pjferrell](https://github.com/pjferrell)) [SIG API Machinery, CLI and Cluster Lifecycle]

* if kube-apiserver is started with `--storage-backend=etcd2`, the media type `application/json` is used. ([#43122](https://github.com/kubernetes/kubernetes/pull/43122), [@liggitt](https://github.com/liggitt))
* API fields that previously serialized null arrays as `null` and empty arrays as `[]` no longer distinguish between those values and always output `[]` when serializing to JSON. ([#43422](https://github.com/kubernetes/kubernetes/pull/43422), [@liggitt](https://github.com/liggitt))

   ([#122276](https://github.com/kubernetes/kubernetes/pull/122276), [@pohly](https://github.com/pohly))
- Added a CBOR implementation of `runtime.Serializer`. Until CBOR graduates to Alpha, API servers will refuse to start if configured with CBOR support. ([#122881](https://github.com/kubernetes/kubernetes/pull/122881), [@benluddy](https://github.com/benluddy))

    <sub-class-of type="application/java-archive"/>
    <glob pattern="*.war"/>
  </mime-type>

  <mime-type type="application/x-tika-unix-dump"/>

  <mime-type type="application/java-serialized-object">
    <glob pattern="*.ser"/>
  </mime-type>

  <mime-type type="application/javascript">
    <alias type="application/x-javascript"/>
    <alias type="text/javascript"/>