Container runtime network not ready: cni config uninitialized

Question

I'm installing kubernetes(kubeadm) on centos VM running inside Virtualbox, so with yum I installed kubeadm, kubelet and docker.

Now while trying to setup cluster with kubeadm init --pod-network-cidr=192.168.56.0/24 --apiserver-advertise-address=192.168.56.33/32 i run into the following error :

Unable to update cni config: No networks found in /etc/cni/net.d

Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

So I checked, no cni folder in /etc even that kubernetes-cni-0.6.0-0.x86_64 is installed. I Tried commenting KUBELET_NETWORK_ARGS in /etc/systemd/system/kubelet.service.d/10-kubeadm.conf but it didn't work.

PS:

• I'm installing behind proxy.

• I have multiple network adapters:

  • NAT : 10.0.2.15/24 for Internet

  • Host Only : 192.168.56.33/32

  • And docker interface : 172.17.0.1/16

Docker version: 17.12.1-ce
kubectl version : Major:"1", Minor:"9", GitVersion:"v1.9.3"
Centos 7

Answer 1

Add pod network add-on

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

If flannel doesn't work, then try calico -

curl https://docs.projectcalico.org/manifests/calico-typha.yaml -o calico.yaml

kubectl apply -f calico.yaml

Answer 2

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