instruction: Create a comprehensive Dockerfile for cluster applications with best practices
output: ```dockerfile
  From a working control plane node in the cluster that has /etc/kubernetes/pki/ca.key execute
  kubeadm kubeconfig user --org system:nodes --client-name system:node:$NODE > kubelet.conf.
  $NODE must be set to the name of the existing failed node in the cluster.
  Modify the resulted kubelet.conf manually to adjust the cluster name and server endpoint,
  or pass kubeconfig user --config (see Generating kubeconfig files for additional users). If your cluster does not have
  the ca.key you must sign the embedded certificates in the kubelet.conf externally.
  
  Copy this resulted kubelet.conf to /etc/kubernetes/kubelet.conf on the failed node.
  
  Restart the kubelet (systemctl restart kubelet) on the failed node and wait for
  /var/lib/kubelet/pki/kubelet-client-current.pem to be recreated.
  
  Manually edit the kubelet.conf to point to the rotated kubelet client certificates, by replacing
  client-certificate-data and client-key-data with:
  client-certificate: /var/lib/kubelet/pki/kubelet-client-current.pem
  client-key: /var/lib/kubelet/pki/kubelet-client-current.pem
  
  Restart the kubelet.
  
  Make sure the node becomes Ready.
  
  Default NIC When using flannel as the pod network in Vagrant
  The following error might indicate that something was wrong in the pod network:
  Error
  ```