- Fixed a bug which the scheduler didn't correctly tell plugins Node deletion.

    * Custom apiservers built with the latest apiserver library will have the 100MB limit on the body of resource requests as well. The limit can be altered via ServerRunOptions.MaxRequestBodyBytes.
    * The body size limit does not apply to subresources like pods/proxy that proxy request content to another server.

- Structured Authentication Configuration now supports `DiscoveryURL`. If specified, `discoveryURL` overrides the URL used to fetch discovery information. This is for scenarios where the well-known and jwks endpoints are hosted at a different location than the issuer (such as locally in the cluster).
   ([#123527](https://github.com/kubernetes/kubernetes/pull/123527), [@aramase](https://github.com/aramase))

- Kubeadm: added the ControlPlaneKubeletLocalMode feature gate. It can be used to tell kubeadm to use the local kube-apiserver endpoint for the kubelet when creating a cluster with "kubeadm init" or when joining control plane nodes with "kubeadm join".  The "kubeadm join" workflow now includes two new experimental phases called "con...

- Added a `kubernetes_feature_enabled` metric which will tell you if a feature is enabled. ([#112652](https://github.com/kubernetes/kubernetes/pull/112652), [@logicalhan](https://github.com/logicalhan))

* Fixes bugs that make apiserver panic when aggregating valid but not well formed OpenAPI spec ([#63635](https://github.com/kubernetes/kubernetes/pull/63635), [@roycaihw](https://github.com/roycaihw))

* Add ipset and udevadm to the hyperkube base image. ([#61357](https://github.com/kubernetes/kubernetes/pull/61357), [@rphillips](https://github.com/rphillips))
* Fixes bugs that make apiserver panic when aggregating valid but not well formed OpenAPI spec ([#63626](https://github.com/kubernetes/kubernetes/pull/63626), [@roycaihw](https://github.com/roycaihw))

* Fixes bugs that make apiserver panic when aggregating valid but not well formed OpenAPI spec ([#63627](https://github.com/kubernetes/kubernetes/pull/63627), [@roycaihw](https://github.com/roycaihw))

  - When registering with a 1.17+ API server, a CustomResourceDefinition conversion webhook can now request that only `v1` ConversionReview requests be sent to them. Previously, conversion webhooks were required to support receiving `v1beta1` ConversionReview requests as well for compatibility with API servers <= 1.15. ([#82707](https://github.com/kubernetes/...

* **[alpha]** New Bootstrap Token authentication and management method. Works well with kubeadm. kubeadm now supports managing tokens, including time based expiration, after the cluster is launched.  See [kubeadm reference docs](https://kubernetes.io/docs/admin/kubeadm/#manage-tokens) for details.