* @throws ConfigPropertyNotFoundException When the property is not found.
     */
    String get(String propertyKey);

    /**
     * Is the property true?
     * @param propertyKey The key of the property which is boolean type. (NotNull)
     * @return The determination, true or false. (if not found, exception)

* kubeadm: add a preflight check that throws a warning if the cgroup driver for Docker on Linux is not "systemd" as per the k8s.io CRI installation guide. ([#73837](https://github.com/kubernetes/kubernetes/pull/73837), [@neolit123](https://github.com/neolit123))

* Kubeadm no longer throws an error for the --cloud-provider=external flag. ([#58259](https://github.com/kubernetes/kubernetes/pull/58259), [@dims](https://github.com/dims))

- Added new `CRDValidationRatcheting` alpha feature. During a PATCH or UPDATE Validation Ratcheting discards errors thrown by unchanged portions of the resource from most OpenAPI schema validations. ([#118990](https://github.com/kubernetes/kubernetes/pull/118990), [@alexzielenski](https://github.com/alexzielenski))

- Kubeadm: the deprecated kube-dns is no longer supported as an option. If "ClusterConfiguration.dns.type" is set to "kube-dns" kubeadm will now throw an error. ([#99646](https://github.com/kubernetes/kubernetes/pull/99646), [@rajansandeep](https://github.com/rajansandeep)) [SIG Cluster Lifecycle]

## Other Notable Changes

### SIG API Machinery

- `kubectl get apiservice` now shows the target service and whether the service is available ([#67747](https://github.com/kubernetes/kubernetes/pull/67747), [@smarterclayton](https://github.com/smarterclayton))

- kubeadm: Added better handling of errors during unmount when calling `kubeadm reset`. When failing to unmount directories under `/var/run/kubelet`, kubeadm will now throw an error instead of showing a warning and continuing to clean up said directory. In such situations, it is better for you to inspect the problem and resolve it manually. Then, you can call `kubeadm reset` again to complete the cleanup.

ontainerd.sock`, Windows: `npipe:////./pipe/containerd-containerd`) instead of the one for Docker. If the `Init|JoinConfiguration.nodeRegistration.criSocket` field is empty during cluster creation and multiple sockets are found on the host always throw an error and ask the user to specify which one to use by setting the value in the field. Make sure you update any kubeadm configuration files on disk, to not include the dockershim socket unless you are still using kubelet version < 1.24 with kubeadm...

- `kube-scheduler`: Optimized implementation of null `labelSelector` in topology spreading. ([#116607](https://github.com/kubernetes/kubernetes/pull/116607), [@alculquicondor](https://github.com/alculquicondor))
- `kubeadm`: now shows a warning message when detecting that the sandbox image of the container runtime is inconsistent with that used by kubeadm ([#115610](https://github.com/kubernetes/kubernetes/pull/115610), [@SataQiu](https://github.com/SataQiu))

- Added a new metric `apiserver_flowcontrol_request_concurrency_in_use` that shows the number of
  seats (concurrency) occupied by the currently executing requests in the API Priority and Fairness system. ([#102795](https://github.com/kubernetes/kubernetes/pull/102795), [@tkashem](https://github.com/tkashem))