* `kubeadm join` is now blocking on the kubelet performing the TLS Bootstrap properly. Earlier, `kubeadm join` only did the discovery part and exited successfully without checking that the kubelet actually started properly and performed the TLS bootstrap correctly. Now, as kubeadm runs some post-join steps (for example, annotating the Node API object with the CRISocket), `kubeadm join` is now waiting for the kubelet to perform the TLS Bootstrap,...

- Kubeadm: remove the deprecated command "kubeadm alpha kubeconfig". Please use "kubeadm kubeconfig" instead. ([#101938](https://github.com/kubernetes/kubernetes/pull/101938), [@knight42](https://github.com/knight42)) [SIG Cluster Lifecycle]

Kubeadm: Expose the `kubeadm join` workflow as phases

- 'kubeadm: marked the flag "--experimental-output'' as deprecated (it will
  be removed in a future release) and added a new flag ''--output" that serves the
  same purpose. Affected commands are - "kubeadm config images list", "kubeadm token

- Kubeadm: The ClusterStatus struct present in the kubeadm-config ConfigMap is deprecated and will be removed on a future version. It is going to be maintained by kubeadm until it gets removed. The same information can be found on `etcd` and `kube-apiserver` pod annotations, `kubeadm.kubernetes.io/etcd.advertise-client-urls` and `kubeadm.kubernetes.io/kube-apiserver.advertise-address.endpoint` respectively. ([#87656](...

- Kubeadm: Fix a bug where kubeadm cannot parse kubelet's version if the latter dumps logs on the standard error. ([#85351](https://github.com/kubernetes/kubernetes/pull/85351), [@rosti](https://github.com/rosti))

  
  kubeadm: Started using `k8s.io/system-validators` `v1.12.1` in `kubeadm` `v1.35`. During `kubeadm init`, `kubeadm join`, and `kubeadm upgrade`, the SystemVerification preflight check throws an error if cgroups v1 is detected and the detected `kubelet` version is `v1.35` or newer. For older versions of `kubelet`, a preflight warning is displayed.
  
  To allow cgroups v1 with `kubeadm` and `kubelet` version `v1.35` or newer, you must:

- kubeadm: removed the deprecated flag `--experimental-output`, please use the flag `--output` instead that serves the same purpose. Affected commands are: `kubeadm config images list`, `kubeadm token list`, `kubeadm upgrade plan`, `kubeadm certs check-expiration`. ([#126914](https://github.com/kubernetes/kubernetes/pull/126914),...

* **[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...

ironment/tools/kubeadm/high-availability/). An entire new test suite has been created specifically for ensuring these features will stay stable over time.

Certificate management has become more robust in 1.15, with kubeadm now seamlessly rotating all your certificates (on upgrades) before they expire. Check the [kubeadm documentation](https://github.com/kubernetes/website/blob/dev-1.15/content/en/docs/reference/setup-tools/kubeadm/kubeadm-alpha.md) for information on how to manage your...