Container runtime network not ready: cni config uninitialized

Add pod network add-on

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml

There are several points to remember when setting up the cluster with "kubeadm init" and it is clearly documented on the Kubernetes site kubeadm cluster create:

• "kubeadm reset" if you have already created a previous cluster
• Remove the ".kube" folder from the home or root directory
• (Also stopping the kubelet with systemctl will allow for a smooth setup)
• Disable swap permanently on the machine, especially if you are rebooting your linux system
• And not to forget, install a pod network add-on according to the instructions provided on the add on site (not Kubernetes site)
• Follow the post initialization steps given on the command window by kubeadm.

If all these steps are followed correctly then your cluster will run properly.

And don't forget to do the following command to enable scheduling on the created cluster:

kubectl taint nodes --all node-role.kubernetes.io/master-

About how to install from behind proxy you may find this useful:

install using proxy

Check this answer.

Use this PR (till will be approved):

kubectl -n kube-system apply -f https://raw.githubusercontent.com/coreos/flannel/bc79dd1505b0c8681ece4de4c0d86c5cd2643275/Documentation/kube-flannel.yml

it's a known issue: coreos/flannel#1044