- kubeadm: improved the overall logic, error handling, and output messages when waiting for the kubelet and API server `/healthz` endpoints to return `OK`. The kubelet and API server checks no longer ran in parallel, but one after another (in serial).
   ([#121958](https://github.com/kubernetes/kubernetes/pull/121958), [@neolit123](https://github.com/neolit123))

- github.com/shirou/gopsutil: c95755e
- github.com/shirou/w32: bb4de01
- github.com/shurcooL/go-goon: 37c2f52
- github.com/shurcooL/go: 9e1955d
- github.com/sourcegraph/go-diff: v0.5.1
- github.com/tarm/serial: 98f6abe
- github.com/tidwall/pretty: v1.0.0
- github.com/timakin/bodyclose: 87058b9
- github.com/ultraware/funlen: v0.0.2
- github.com/urfave/cli: v1.20.0
- github.com/valyala/bytebufferpool: v1.0.0

- Bumped cadvisor version to `v0.47.3`. ([#119225](https://github.com/kubernetes/kubernetes/pull/119225), [@iholder101](https://github.com/iholder101))
- CI job `ci-kubernetes-node-arm64-ubuntu-serial` will test node e2e on arm64, `use-dockerized-build` and `target-build-arch` are required to run this job. ([#118567](https://github.com/kubernetes/kubernetes/pull/118567), [@chendave](https://github.com/chendave))

    /**
     * The simple implementation for configuration.
     * @author FreeGen
     */
    public static class SimpleImpl extends FessEnv.SimpleImpl implements FessConfig {

        /** The serial version UID for object serialization. (Default) */
        private static final long serialVersionUID = 1L;

        public String getDomainTitle() {
            return get(FessConfig.DOMAIN_TITLE);
        }

  </mime-type>

  <mime-type type="application/sereal">
    <_comment>Sereal binary serialization format</_comment>
    <tika:link>https://github.com/Sereal/Sereal/blob/master/sereal_spec.pod</tika:link>
    <glob pattern="*.srl"/>
  </mime-type>
  <mime-type type="application/sereal;version=1">
    <sub-class-of type="application/sereal"/>
    <magic priority="50">

  // Time when this Event was first observed.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.MicroTime eventTime = 10;

  // Data about the Event series this event represents or nil if it's a singleton Event.
  // +optional
  optional EventSeries series = 11;

  // What action was taken/failed regarding to the Regarding object.
  // +optional
  optional string action = 12;

- Changed kubectl `--subresource` flag to beta ([#116595](https://github.com/kubernetes/kubernetes/pull/116595), [@MadhavJivrajani](https://github.com/MadhavJivrajani))
- Changed metrics for aggregated discovery to publish new time series (alpha). ([#115630](https://github.com/kubernetes/kubernetes/pull/115630), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery and Testing]

* The `--authorization-rbac-super-user` flag (alpha in 1.5) is deprecated; the `system:masters` group has privileged access ([#38121](https://github.com/kubernetes/kubernetes/pull/38121), [@deads2k](https://github.com/deads2k))

## Changelog since v1.18.16

## Changes by Kind

### Failing Test

- Fix handing special characters in the volume path on Windows ([#99138](https://github.com/kubernetes/kubernetes/pull/99138), [@yujuhong](https://github.com/yujuhong)) [SIG Storage]

### Bug or Regression

## Major Themes

Kubernetes is developed by community members whose work is organized into
[Special Interest Groups][]. For the 1.8 release, each SIG provides the
themes that guided their work.

[Special Interest Groups]: https://github.com/kubernetes/community/blob/master/sig-list.md

### SIG API Machinery