Container runtime network not ready: cni config un

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

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

Answer 2

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

Answer 3

I could not see the helm server version:

$ helm version --tiller-namespace digital-ocean-namespace
Client: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}
Error: could not find a ready tiller pod

The kubectl describe node kubernetes-master --namespace digital-ocean-namespace command was showing the message:

NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

The nodes was not ready:

$ kubectl get node --namespace digital-ocean-namespace
NAME                  STATUS     ROLES    AGE   VERSION
kubernetes-master     NotReady   master   82m   v1.14.1
kubernetes-worker-1   NotReady   <none>   81m   v1.14.1

I had a version compatibility issue between Kubernetes and the flannel network.

My k8s version was 1.14 as seen in the command:

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.1", GitCommit:"b7394102d6ef778017f2ca4046abbaa23b88c290", GitTreeState:"clean", BuildDate:"2019-04-08T17:11:31Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.1", GitCommit:"b7394102d6ef778017f2ca4046abbaa23b88c290", GitTreeState:"clean", BuildDate:"2019-04-08T17:02:58Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}

After re-installing the flannel network with the command:

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

I could then see the helm server version:

$ helm version --tiller-namespace digital-ocean-namespace
Client: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}

Answer 4

It was a proxy error as mentionned in Github https://github.com/kubernetes/kubernetes/issues/34695

They suggested to use kubeadm init --use-kubernetes-version v1.4.1 but i change my network entirely (no proxy) and i manage to setup my cluster.

After that we can setup pod network with kubectl apply -f ... see https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/#pod-network

Answer 5

Add pod network add-on

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

Answer 6

I face the same errors and it seens that It seens that systemd have a problems. I'm not remember my last systemd version. But update it solve the problems for me.