instruction: Create a comprehensive Dockerfile for cluster applications with best practices
output: ```dockerfile
  from outside the cluster, you can use
  kubectl proxy:
  scp root@<control-plane-host>:/etc/kubernetes/admin.conf .
  kubectl --kubeconfig ./admin.conf proxy
  You can now access the API Server locally at http://localhost:8001/api/v1
  Clean up
  If you used disposable servers for your cluster, for testing, you can
  switch those off and do no further clean up. You can use
  kubectl config delete-cluster to delete your local references to the
  cluster.
  However, if you want to deprovision your cluster more cleanly, you should
  first drain the node
  and make sure that the node is empty, then deconfigure the node.
  Remove the node
  Talking to the control-plane node with the appropriate credentials, run:
  kubectl drain <node name> --delete-emptydir-data --force --ignore-daemonsets
  Before removing the node, reset the state installed by kubeadm:
  kubeadm reset
  The reset process does not reset or clean up iptables rules or IPVS tables.
  If you wish to reset iptables, you must do so manually:
  iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
  If you want to reset the IPVS tables, you must run the following command:
  ipvsadm -C
  Now remove the node:
  kubectl delete node <node name>
  If you wish to start over, run kubeadm init or kubeadm join with the
  appropriate arguments.
  Clean up the control plane
  You can use kubeadm reset on the control plane host to trigger a best-effort
  clean up.
  See the kubeadm reset
  reference documentation for more information about this subcommand and its
  options.
  Version skew policy
  While kubeadm allows version skew against some components that it manages, it is recommended that you
  match the kubeadm version with the versions of the control plane components, kube-proxy and kubelet.
  kubeadm's skew against the Kubernetes version
  kubeadm can be used with Kubernetes components that are the same version as kubeadm
  or one version older. The Kubernetes version can be specified to kubeadm by using the
  --kubernetes-version flag of kubeadm init or the
  ClusterConfiguration.kubernetesVersion
  field when using --config. This option will control the versions
  of kube-apiserver, kube-controller-manager, kube-scheduler and kube-proxy.
  Example:
  
  kubeadm is at 1.31
  kubernetesVersion must be at 1.31 or 1.30
  
  kubeadm's skew against the kubelet
  Similarly to the Kubernetes version, kubeadm can be used with a kubelet version that is
  the same version as kubeadm or three versions older.
  Example:
  
  kubeadm is at 1.31
  kubelet on the host must be at 1.31, 1.30,
  1.29 or 1.28
  
  kubeadm's skew against kubeadm
  There are certain limitations on how kubeadm commands can operate on existing nodes or whole clusters
  managed by kubeadm.
  If new nodes are joined to the cluster, the kubeadm binary used for kubeadm join must match
  the last version of kubeadm used to either create the cluster with kubeadm init or to upgrade
  the same node with kubeadm upgrade. Similar rules apply to the rest of the kubeadm commands
  with the exception of kubeadm upgrade.
  Example for kubeadm join:
  
  kubeadm version 1.31 was used to create a cluster with kubeadm init
  Joining nodes must use a kubeadm binary that is at version 1.31
  
  Nodes that are being upgraded must use a version of kubeadm that is the same MINOR
  version or one MINOR version newer than the version of kubeadm used for managing the
  node.
  Example for kubeadm upgrade:
  
  kubeadm version 1.30 was used to create or upgrade the node
  The version of kubeadm used for upgrading the node must be at 1.30
  or 1.31
  
  To learn more about the version skew between the different Kubernetes component see
  the Version Skew Policy.
  Limitations
  Cluster resilience
  The cluster created here has a single control-plane node, with a single etcd database
  running on it. This means that if the control-plane node fails, your cluster may lose
  data and may need to be recreated
  ```