- Kubeadm: add a upgrade health check that deploys a Job ([#81319](https://github.com/kubernetes/kubernetes/pull/81319), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]
- Kubeadm: add the experimental feature gate PublicKeysECDSA that can be used to create a

* kubeadm now accepts `--apiserver-extra-args`, `--controller-manager-extra-args` and `--scheduler-extra-args`, making it possible to override / specify additional flags for control plane components. One good example is to deploy Kubernetes with a different admission-control flag on API server. ([#58080](https://github.com/kubernetes/kubernetes/pull/58080), [@simonferquel](https://github.com/simonferquel))

- CoreDNS is only officially supported on Linux at this time.  As such, when kubeadm is used to deploy this component into your kubernetes cluster, it will be restricted (using `nodeSelectors`) to run only on nodes with that operating system. This ensures that in clusters which include Windows nodes, the scheduler will not ever attempt to place CoreDNS...

incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly)) [SIG Scheduling]

### Other (Cleanup...

* Stackdriver cluster logging now deploys a new component to export Kubernetes events. ([#46700](https://github.com/kubernetes/kubernetes/pull/46700), [@crassirostris](https://github.com/crassirostris))

  // PreStop hook is executed. Regardless of the outcome of the handler, the
  // container will eventually terminate within the Pod's termination grace
  // period (unless delayed by finalizers). Other management of the container blocks until the hook completes
  // or until the termination grace period is reached.

- Introduce `node.kubernetes.io/exclude-balancer` and `node.kubernetes.io/exclude-disruption` labels in alpha to prevent cluster deployers from being dependent on the optional `node-role` labels which not all clusters may provide. ([#80238](https://github.com/kubernetes/kubernetes/pull/80238), [@smarterclayton](https://github.com/smarterclayton))

incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly)) [SIG Scheduling]

### Other (Cleanup...

features and stability work required for bootstrapping production clusters efficiently. kubeadm has promoted high availability (HA) capability to beta, allowing users to use the familiar `kubeadm init` and `kubeadm join` commands to [configure and deploy an HA control plane](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/). An entire new test suite has been created specifically for ensuring these features will stay stable over time.

Certificate...

    <glob pattern="*.dist"/>
    <glob pattern="*.distz"/>
    <glob pattern="*.pkg"/>
    <glob pattern="*.bpk"/>
    <glob pattern="*.dump"/>
    <glob pattern="*.elc"/>
    <glob pattern="*.deploy"/>
  </mime-type>

  <mime-type type="application/oda">
    <glob pattern="*.oda"/>
  </mime-type>
  <mime-type type="application/oebps-package+xml">
    <glob pattern="*.opf"/>
  </mime-type>