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* Implemented `kubeadm upgrade plan` for checking whether you can upgrade your cluster to a newer version ([#48899](https://github.com/kubernetes/kubernetes/pull/48899), [@luxas](https://github.com/luxas))
    * Implemented `kubeadm upgrade apply` for upgrading your cluster from one version to an other

#### kubectl:

* kubernetes-worker juju charm: Added support for setting the --enable-ssl-chain-completion option on the ingress proxy.  "action required": if your installation relies on supplying incomplete certificate chains and using OCSP to fill them in, you must set "ingress-ssl-chain-completion" to "true" in your juju configuration. ([#63845](https://github.com/kubernetes/kubernetes/pull/63845), [@paulgear](https://github.com/paulgear))

 - CephFS volume plugin (`kubernetes.io/cephfs`) has been deprecated in this release and will be removed in a subsequent release. The alternative is to use the CephFS CSI driver (https://github.com/ceph/ceph-csi/) in your Kubernetes cluster. ([#118143](https://github.com/kubernetes/kubernetes/pull/118143), [@humblec](https://github.com/humblec))
 - Deprecated support for CSI migration of `Ceph RBD volumes`. Users who were relying on Kubernetes' ability