InformationVerify kubelet's certificate before establishing connection.
The connections from the apiserver to the kubelet are used for fetching logs for pods, attaching (through kubectl) to running pods, and using the kubelet's port-forwarding functionality. These connections terminate at the kubelet's HTTPS endpoint. By default, the apiserver does not verify the kubelet's serving certificate, which makes the connection subject to man-in-the-middle attacks, and unsafe to run over untrusted and/or public networks.
SolutionFollow the Kubernetes documentation and setup the TLS connection between the apiserver and kubelets. Then, edit the `/etc/kubernetes/apiserver` file on the master node and set the `KUBE_API_ARGS` parameter to `'--kubelet-certificate-authority='`: `KUBE_API_ARGS='--kubelet-certificate-authority='`
Based on your system, restart the `kube-apiserver` service. For example: `systemctl restart kube-apiserver.service`
You require TLS to be configured on apiserver as well as kubelets.