- The feature gate `RootCAConfigMap` graduated to GA in v1.21 and therefore will be unconditionally enabled. This flag will...

* Restored the pre-1.10 behavior of the openstack cloud provider, which uses the instance name as the Kubernetes Node name. This requires instances be named with RFC-1123 compatible names. ([#63903](https://github.com/kubernetes/kubernetes/pull/63903), [@liggitt](https://github.com/liggitt))

- Kubeadm: external etcd endpoints passed in the `ClusterConfiguration` that have Unicode characters are no longer IDNA encoded (converted to Punycode). They are now just URL encoded as per Go's implementation of RFC-3986, have duplicate "/" removed from the URL paths, and passed like that directly to the `kube-apiserver` `--etcd-servers` flag. If you have etcd endpoints that have Unicode characters, it is advisable to encode them in advance with tooling that is...

- Modify DNS-1123 error messages to indicate that RFC 1123 is not followed exactly ([#94182](https://github.com/kubernetes/kubernetes/pull/94182), [@mattfenwick](https://github.com/mattfenwick)) [SIG API Machinery, Apps, Auth, Network and Node]

* Fix log spam due to unnecessary status update when node is deleted. ([#45923](https://github.com/kubernetes/kubernetes/pull/45923), [@verult](https://github.com/verult))
* GCE installs will now avoid IP masquerade for all RFC-1918 IP blocks, rather than just 10.0.0.0/8.  This means that clusters can ([#46473](https://github.com/kubernetes/kubernetes/pull/46473), [@thockin](https://github.com/thockin))

* Restores the pre-1.10 behavior of the openstack cloud provider which uses the instance name as the Kubernetes Node name. This requires instances be named with RFC-1123 compatible names. ([#63903](https://github.com/kubernetes/kubernetes/pull/63903), [@liggitt](https://github.com/liggitt))