Kubernetes Cluster Creation problem

I am following the Certified Kubernetes Administrator course.
After setting up the practise cluster (1 master and 2 nodes), I joined two nodes to the cluster. However when I do kubectl get nodes, I see all the 3 servers' status to be "NotReady". 
When I tried "kubectl describe nodes", I see the following

Ready False Tue, 23 Oct 2018 23:18:55 +0000 Tue, 23 Oct 2018 23:15:45 +0000 KubeletNotReady runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

I looked up for troubleshooting and the most common one was to remove  $KUBELET_NETWORK_ARGS in 
However, I do not have $KUBELET_NETWORK_ARGS in the above file.

Kubelet service is enabled and started.

Can anyone suggest what I am missing please?


  • post-author-pic
    Terrence C

    Be sure you are always using the cloud servers private IP addresses for configuring your cluster. The ports necessary to manage, join and deploy services won't be available on the public IPs.

  • post-author-pic
    Prudhvi V

    Thanks, I will try to recreate the cluster.

  • post-author-pic
    Victor C

    Also, use the updated flannel network plugin,

    kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

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