// kubelet.  If the kubelet is configured to verify the apiserver's TLS credentials, it does not mean the
  // connection to the real kubelet is vulnerable to a man in the middle attack (e.g. an attacker could not intercept
  // the actual log data coming from the real kubelet).
  // +optional
  optional bool insecureSkipTLSVerifyBackend = 9;
}

* kubelets are no longer allowed to delete their own Node API object. Prior to 1.11, in rare circumstances related to cloudprovider node ID changes, kubelets would attempt to delete/recreate their Node object at startup. Kubelets older than 1.11 are not supported running against a v1.13+ API server. If an unsupported legacy kubelet encounters this situation, a cluster admin can remove the Node object: ([#71021](htt...

 ([#64792](https://github.com/kubernetes/kubernetes/pull/64792), [@luxas](https://github.com/luxas))

* Fix the bug that query Kubelet's stats summary with CRI stats enabled results in error. ([#53107](https://github.com/kubernetes/kubernetes/pull/53107), [@Random-Liu](https://github.com/Random-Liu))

      - [kube-apiserver:](#kube-apiserver)
      - [kubelet:](#kubelet)
      - [kubectl:](#kubectl)
      - [client-go:](#client-go)
  - [Changes by Kind](#changes-by-kind-20)
    - [Deprecation](#deprecation)
      - [kube-apiserver:](#kube-apiserver-1)
      - [kube-controller-manager:](#kube-controller-manager)
      - [kubelet:](#kubelet-1)
      - [kube-proxy:](#kube-proxy)
      - [kubeadm:](#kubeadm)

    * "client-certificate: /var/lib/kubelet/pki/kubelet-client-current.pem" and "client-key: /var/lib/kubelet/pki/kubelet-client-current.pem", replacing the embedded client certificate and key.
* action required: kubeadm deprecates the use of the hyperkube image ([#85094](https://github.com/kubernetes/kubernetes/pull/85094), [@rosti](https://github.com/rosti))

### Other notable changes

### Node Components
* **Kubelet with the Docker-CRI implementation**
  * The Docker-CRI implementation is enabled by default.
  * It is not compatible with containers created by older Kubelets. It is
    recommended to drain your node before upgrade. If you choose to perform
    an in-place upgrade, the Kubelet will automatically restart all
    Kubernetes-managed containers on the node.

- kubelet: Users can now enable the alpha NodeLease feature gate to have the Kubelet create and periodically renew a Lease in the kube-node-lease namespace. The lease duration defaults to 40s, and can be configured via the kubelet.config.k8s.io/v1beta1.KubeletConfiguration's NodeLeaseDurationSeconds field. ([#66257](https://github.com/kubernetes/kubernetes/pull/66257),...

* action required: Deprecate the kubelet's cadvisor port. The default will change to 0 (disabled) in 1.12, and the cadvisor port will be removed entirely in 1.13. ([#59827](https://github.com/kubernetes/kubernetes/pull/59827), [@dashpole](https://github.com/dashpole))

* [alpha] Rotation of the server TLS certificate on the kubelet. See [TLS bootstrapping - approval controller](https://kubernetes.io/docs/admin/kubelet-tls-bootstrapping/#approval-controller).

* [alpha] Rotation of the client TLS certificate on the kubelet. See [TLS bootstrapping - kubelet configuration](https://kubernetes.io/docs/admin/kubelet-tls-bootstrapping/#kubelet-configuration).