Error while starting POD in a newly created kubernetes cluster (ContainerCreating) - kubernetes

Question

I am new to Kubernetes. I have created a Kubernetes cluster with one Master node and 2 worker nodes. I have installer helm for the deployment of apps. I am getting the following error while starting the tiller pod
tiller-deploy-5b4685ffbf-znbdc 0/1 ContainerCreating 0 23h
After describing the pod I got the following result
[root#master-node flannel]# kubectl --namespace kube-system describe
pod tiller-deploy-5b4685ffbf-znbdc
Events:
Type Reason Age From Message
Warning FailedCreatePodSandBox 10m (x34020 over 22h) kubelet,
worker-node1 (combined from similar events): Failed to create pod
sandbox: rpc error: code = Unknown desc = failed to set up sandbox
container
"cdda0a8ae9200668a2256e8c7b41904dce604f73f0282b0443d972f5e2846059"
network for pod "tiller-deploy-5b4685ffbf-znbdc": networkPlugin cni
failed to set up pod "tiller-deploy-5b4685ffbf-znbdc_kube-system"
network: open /run/flannel/subnet.env: no such file or directory
Normal SandboxChanged 25s (x34556 over 22h) kubelet, worker-node1 Pod
sandbox changed, it will be killed and re-created.
Any hint of how can I get away with this error.

Answer 1

You need to setup a CNI plugin such as Flannel. Verify if all the pods in kube-system namespace are running.
To apply flannel in you cluster run the following command:
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml
For flannel to work correctly pod-network-cidr should be 10.244.0.0/16 or if you have a different CIDR, you can customize flannel manifest (kube-flannel.yml) according to your needs.
Example:
net-conf.json: |
{
"Network": "10.10.0.0/16",
"Backend": {
"Type": "vxlan"
}