- Introduces extension point for external feedback on pod readiness.
kubernetes/kubernetes: [#74434](http://github.com/kubernetes/kubernetes/pull/74434),
kubernetes/enhancements: [#580](https://github.com/kubernetes/enhancements/issues/580) [[kep](https://github.com/kubernetes/enhancements/blob/master/keps/sig-network/580-pod-readiness-gates/README.md)]

Kubeadm: Automate certificate copy between control planes in HA setups

- [Conformance tests](https://github.com/kubernetes/kubernetes/pull/108592) added support for Windows
- New repository created for [Windows Operational Readiness](https://github.com/kubernetes-sigs/windows-operational-readiness)

### Moved container registry service from k8s.gcr.io to registry.k8s.io

specified) is `1s` which may be too small for some exec probes. Ensure that pods relying on this behavior are updated to correctly handle probe timeouts. See [configure probe](https://docs.k8s.io/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#configure-probes) section of the documentation for more details.

  - This change in behavior may be unexpected for some clusters and can be disabled by turning off the `ExecProbeTimeout` feature gate. This gate will be...

- Kube-apiserver: Each unique set of etcd server overrides specified with `--etcd-servers-overrides` surfaced health checks named `etcd-override-<index>` and `etcd-override-readiness-<index>`. These checks were still excluded by the `?exclude=etcd` and `?exclude=etcd-readiness` directives. ([#129438](https://github.com/kubernetes/kubernetes/pull/129438), [@pacoxu](https://github.com/pacoxu)) [SIG API Machinery and Testing]

## Changelog since v1.16.0

### Other notable changes

* Limit the body length of exec readiness/liveness probes. remote CRIs and Docker shim read a max of 16MB output of which the exec probe itself inspects 10kb. ([#82514](https://github.com/kubernetes/kubernetes/pull/82514), [@dims](https://github.com/dims))

- Pods will now post their readiness during termination. ([#110417](https://github.com/kubernetes/kubernetes/pull/110417), [@aojea](https://github.com/aojea)) [SIG Network, Node and Testing]

- Added readiness gates in extended output for pods ([#70775](https://github.com/kubernetes/kubernetes/pull/70775), [@freehan](https://github.com/freehan))

- Pods will now post their readiness during termination. ([#110418](https://github.com/kubernetes/kubernetes/pull/110418), [@aojea](https://github.com/aojea)) [SIG Network, Node and Testing]

      * If you are using plugins other than `bridge`, make sure you have
        updated custom plugins to the latest version that is compatible.
* **CNI plugins now affect node readiness**
  * Kubelet will now block node readiness until a CNI configuration file is
    present in `/etc/cni/net.d` or a given custom CNI configuration path.
    [This change](https://github.com/kubernetes/kubernetes/pull/43474) ensures

### Bug or Regression

- Fix 121094 by re-introducing the readiness predicate for externalTrafficPolicy: Local services. ([#121116](https://github.com/kubernetes/kubernetes/pull/121116), [@alexanderConstantinescu](https://github.com/alexanderConstantinescu)) [SIG Cloud Provider and Network]