release.  A new alpha feature is introduced to improve the mechanism that nodes heartbeat back to the control plane.  The `NodeLease` feature results in the node using a `Lease` resource in the `kube-node-lease` namespace that is renewed periodically.  The `NodeStatus` that was used previously to heartbeat back to the control plane is only updated when it changes.  This reduces load on the control plane for large clusters. The Kubelet plugin registration mechanism, which enables automatic discovery of external...

- Kubeadm: only taint control plane nodes when the legacy "master" taint is present. This avoids the bug where "kubeadm upgrade" will re-taint a control plane  node with the new "control plane" taint even if the user explicitly untainted the node. ([#109840](https://github.com/kubernetes/kubernetes/pull/109840), [@neolit123](https://github.com/neolit123))

- Show a warning message to inform users that the `legacy` profile is planned to be deprecated. ([#127230](https://github.com/kubernetes/kubernetes/pull/127230), [@mochizuki875](https://github.com/mochizuki875)) [SIG CLI]

  - The `kubeadm upgrade node config` and `kubeadm upgrade node experimental-control-plane` commands are deprecated in favor of `kubeadm upgrade node`, and will be removed in a future release. ([#78408](https://github.com/kubernetes/kubernetes/pull/78408), [@fabriziopandini](https://github.com/fabriziopandini))

It could be used to tell kubeadm to wait for all control plane components to be ready when running "kubeadm init" or "kubeadm join --control-plane". Previously, kubeadm only waited for the kube-apiserver. The "kubeadm join" workflow now includes a new experimental phase called "wait-control-plane". This phase was marked as non-experimental when WaitForAllControlPlaneComponents became GA. Accordingly, a "kubeadm init" phase "wait-control-plane" was also available once WaitForAllControlPlaneComponents...

  * Verification against Kubernetes 1.8 is planned soon after the release.

* [stable] [frakti](https://github.com/kubernetes/frakti): CRI implementation for hypervisor-based runtimes is now v1.1. [[@feiskyer](https://github.com/feiskyer)]

  * Enhance CNI plugin compatibility, supports flannel, calico, weave and so on.

Additionally, since the information returned from the discovery APIs may change dynamically, a cache of the results should not be considered authoritative.
ETag support is planned in a future version to facilitate client caching.
([#47977](https://github.com/kubernetes/kubernetes/pull/47977), [#44957](https://github.com/kubernetes/kubernetes/pull/44957))

Kubeadm: Automate certificate copy between control planes in HA setups

- Joining control plane nodes to a HA cluster can now be simplified by enabling the optional automatic copy of certificates from an existing control plane node.
- You can now use `kubeadm init --experimental-upload-certs` and `kubeadm join --experimental-control-plane --certificate-key`.

### Deploy a more secure control plane with kubeadm

A new alpha feature allows running the kubeadm control plane components as non-root users. This is a long requested security measure in kubeadm. To try it you must enable the kubeadm-specific `RootlessControlPlane` feature gate. When you deploy a cluster using this alpha feature, your control plane runs with lower privileges.

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 "control-plane-join-etcd" and "kubelet-wait-bootstrap" which will be used when the feature gate is enabled. This phases will be marked as non-experimental when ControlPlaneKubeletLocalMode becomes GA. During...