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...

* **[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...

- Improved air-gapped and offline support
  - kubeadm now handles air-gapped environments by using the local client version as a fallback.
  - Some kubeadm commands are now allowed to work in a completely offline mode.
- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.

- Kubeadm: deprecate self-hosting support. The experimental command "kubeadm alpha self-hosting" is now deprecated and will be removed in a future release. ([#95125](https://github.com/kubernetes/kubernetes/pull/95125), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- kubeadm: if the `NodeLocalCRISocket` feature gate is enabled, remove the `kubeadm.alpha.kubernetes.io/cri-socket` annotation from a given node on `kubeadm upgrade`. ([#129279](https://github.com/kubernetes/kubernetes/pull/129279), [@HirazawaUi](https://github.com/HirazawaUi)) [SIG Cluster Lifecycle and Testing]

- Kubeadm: `kubeadm config view` command has been deprecated and will be removed in a feature release, please use `kubectl get cm -o yaml -n kube-system kubeadm-config` to get the kubeadm config directly ([#92740](https://github.com/kubernetes/kubernetes/pull/92740), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

- kubeadm: added the `WaitForAllControlPlaneComponents` feature gate. 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...

- Fix error handling and potential go null pointer exception in kubeadm upgrade diff ([#80648](https://github.com/kubernetes/kubernetes/pull/80648), [@odinuge](https://github.com/odinuge))
- kubeadm: fall back to client version in case of certain HTTP errors ([#80024](https://github.com/kubernetes/kubernetes/pull/80024), [@RainbowMango](https://github.com/RainbowMango))

- Kubeadm: deprecated command "alpha selfhosting pivot" is now removed. ([#97627](https://github.com/kubernetes/kubernetes/pull/97627), [@knight42](https://github.com/knight42))

 - The default Bootstrap Token created with `kubeadm init` v1.8 expires
 and is deleted after 24 hours by default to limit the exposure of the
 valuable credential. You can create a new Bootstrap Token with
 `kubeadm token create` or make the default token permanently valid by specifying
 `--token-ttl 0` to `kubeadm init`. The default token can later be deleted with
 `kubeadm token delete`.