title: Unauthorized when trying to allow nodes to join a Kubernetes cluster
body: <p>I had a two node cluster in which one was master and another slave. It was running from the last 26 days. Today i tried to remove a node using kubeadm reset and add it again and kubelet was not able to start</p>
  
  <pre><code>cni.go:171] Unable to update cni config: No networks found in /etc/cni/net.d
  The binary conntrack is not installed, this can cause failures in network connection cleanup.
  server.go:376] Version: v1.10.2
  feature_gate.go:226] feature gates: &amp;{{} map[]}
  plugins.go:89] No cloud provider specified.
  server.go:233] failed to run Kubelet: cannot create certificate signing request: Unauthorized
  </code></pre>
  
  <p>while the join command is successful</p>
  
  <pre><code>[preflight] Running pre-flight checks.
  [WARNING FileExisting-crictl]: crictl not found in system path
  Suggestion: go get github.com/kubernetes-incubator/cri-tools/cmd/crictl
  [preflight] Starting the kubelet service
  [discovery] Trying to connect to API Server "aaaaa:6443"
  [discovery] Created cluster-info discovery client, requesting info from "https://aaaaa:6443"
  [discovery] Requesting info from "https:/aaaaaa:6443" again to validate TLS against the pinned public key
  [discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server
  [discovery] Successfully established connection with API Server "aaaa:6443"
  
  This node has joined the cluster:
  
  Certificate signing request was sent to master and a response
  was received.
  The Kubelet was informed of the new secure connection details.
  
  Run 'kubectl get nodes' on the master to see this node join the cluster.
  </code></pre>
  
  <p>IMO the log failed to run Kubelet: cannot create certificate signing request: Unauthorized is the source of the problem, but I am do not know how it is coming and how to fix it.</p>
  
  <p>TIA. I can give more details but I am not sure what all I shall give</p>