- kubeadm: `kubeadm upgrade node` now supports `addon` and `post-upgrade` phases. Users can use `kubeadm upgrade node phase addon` to execute the addon upgrade, or use `kubeadm upgrade node...

- Kubeadm:...

  - **apiserver_flowcontrol_priority_level_seat_count_watermarks**: histograms of high and low watermarks of number of seats occupied by executing requests (both regular and final-delay phases included), broken down by priority_level.

Kubeadm: Expose the `kubeadm join` workflow as phases

- kubeadm now includes the ability to specify certificate encryption and decryption keys for the upload and download certificate phases as part of the new v1beta2 kubeadm config format. ([#77012](https://github.com/kubernetes/kubernetes/pull/77012), [@rosti](https://github.com/rosti))

- If `kubeadm reset` finds no etcd member ID for the peer it removes during the `remove-etcd-member` phase, it continues immediately to other phases, instead of retrying the phase for up to 3 minutes before continuing. ([#117916](https://github.com/kubernetes/kubernetes/pull/117916), [@dlipovetsky](https://github.com/dlipovetsky)) [SIG Cluster Lifecycle]

- If `kubeadm reset` finds no etcd member ID for the peer it removes during the `remove-etcd-member` phase, it continues immediately to other phases, instead of retrying the phase for up to 3 minutes before continuing. ([#117724](https://github.com/kubernetes/kubernetes/pull/117724), [@dlipovetsky](https://github.com/dlipovetsky)) [SIG Cluster Lifecycle]

   ([#123341](https://github.com/kubernetes/kubernetes/pull/123341), [@neolit123](https://github.com/neolit123))

- kubeadm: Avoided loading the file passed to `--kubeconfig` during `kubeadm init` phases more than once. ([#129006](https://github.com/kubernetes/kubernetes/pull/129006), [@kokes](https://github.com/kokes))

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 "kubeadm upgrade" commands, if the feature gate is enabled, modify the "/etc/kubernetes/kubelet.conf...