* Renamed the API server flag `--experimental-bootstrap-token-auth` to `--enable-bootstrap-token-auth`. The old value is accepted with a warning in 1.8 and will be removed in 1.9. ([#51198](https://github.com/kubernetes/kubernetes/pull/51198), [@mattmoyer](https://github.com/mattmoyer))

- The deprecated `--experimental-bootstrap-kubeconfig` flag has been removed.
  This can be set via `--bootstrap-kubeconfig`. ([#103172](https://github.com/kubernetes/kubernetes/pull/103172), [@niulechuan](https://github.com/niulechuan))

### API Change

- kubeadm: You can now delete multiple bootstrap tokens at once. ([#75646](https://github.com/kubernetes/kubernetes/pull/75646), [@bart0sh](https://github.com/bart0sh))

- Migrated the bootstrap signer controller and the token cleaner controller (within `kube-controller-manager`) to use [contextual logging](https://k8s.io/docs/concepts/cluster-administration/system-logs/#contextual-logging). ([#113464](https://github.com/kubernetes/kube...

- kubeadm: The kubeadm configuration now supports the definition of more than one control plane instances with their own APIEndpoint. The APIEndpoint for the "bootstrap" control plane instance should be defined using `InitConfiguration.APIEndpoint`, while the APIEndpoints for additional control plane instances should be added using `JoinConfiguration.APIEndpoint`. ([#67832](https://github.com/kubernetes/kubernetes/pull/67832),...

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...

* Set an upper bound (5 minutes) on how long the Kubelet will wait before exiting when the client cert from disk is missing or invalid. This prevents the Kubelet from waiting forever without attempting to bootstrap a new client credentials. ([#59316](https://github.com/kubernetes/kubernetes/pull/59316), [@smarterclayton](https://github.com/smarterclayton))

- We no longer allow the cluster operator to delete any suggested priority & fairness bootstrap configuration object. If a cluster operator removes a suggested configuration, it will be restored by the apiserver. ([#102067](https://github.com/kubernetes/kubernetes/pull/102067), [@tkashem](https://github.com/tkashem))

                        Valid Options: LISTENER, FILTER_CHAIN, NETWORK_FILTER, HTTP_FILTER, ROUTE_CONFIGURATION, VIRTUAL_HOST, HTTP_ROUTE, CLUSTER, EXTENSION_CONFIG, BOOTSTRAP, LISTENER_FILTER
                      enum:
                      - INVALID
                      - LISTENER
                      - FILTER_CHAIN
                      - NETWORK_FILTER

- Kubeadm: added the "--cleanup-tmp-dir" flag for `kubeadm reset`. It will cleanup the contents of `/etc/kubernetes/tmp`....