Coredns in pending state in Kubernetes cluster v1.19.4

Question

I'm trying to configure a kubernetes cluster with 1 master and 2 workers after doing all the configuration and initializing the cluster I keep getting pending status on coredns

kube-system   coredns-f9fd979d6-7c7fp                 0/1     Pending   0          26h   <none>         <none>          <none>           <none>                 
kube-system   coredns-f9fd979d6-xpf6d                 0/1     Pending   0          26h   <none>         <none>          <none>           <none>
kube-system   etcd-l00301c002075                      1/1     Running   0          26h   10.87.22.132   l00301c002075   <none>           <none>
kube-system   kube-apiserver-l00301c002075            1/1     Running   0          26h   10.87.22.132   l00301c002075   <none>           <none>
kube-system   kube-controller-manager-l00301c002075   1/1     Running   1          26h   10.87.22.132   l00301c002075   <none>           <none>
kube-system   kube-proxy-mrzbx                        1/1     Running   0          26h   10.87.22.132   l00301c002075   <none>           <none>
kube-system   kube-scheduler-l00301c002075            1/1     Running   1          26h   10.87.22.132   l00301c002075   <none>           <none>

here the output of the kubelet status

L00301C002075 kubelet[3996]: W1126 16:10:01.023901    3996 cni.go:239] Unable to update cni config: no networks found in /etc/cni/net.d
Nov 26 16:10:03 L00301C002075 kubelet[3996]: E1126 16:10:03.242440    3996 kubelet.go:2103] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized
Nov 26 16:10:06 L00301C002075 kubelet[3996]: W1126 16:10:06.024105    3996 cni.go:239] Unable to update cni config: no networks found in /etc/cni/net.d
Nov 26 16:10:08 L00301C002075 kubelet[3996]: E1126 16:10:08.243924    3996 kubelet.go:2103] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized
Nov 26 16:10:11 L00301C002075 kubelet[3996]: W1126 16:10:11.024305    3996 cni.go:239] Unable to update cni config: no networks found in /etc/cni/net.d
Nov 26 16:10:13 L00301C002075 kubelet[3996]: E1126 16:10:13.245176    3996 kubelet.go:2103] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized
Nov 26 16:10:16 L00301C002075 kubelet[3996]: W1126 16:10:16.024604    3996 cni.go:239] Unable to update cni config: no networks found in /etc/cni/net.d
Nov 26 16:10:18 L00301C002075 kubelet[3996]: E1126 16:10:18.246664    3996 kubelet.go:2103] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized
Nov 26 16:10:21 L00301C002075 kubelet[3996]: W1126 16:10:21.024786    3996 cni.go:239] Unable to update cni config: no networks found in /etc/cni/net.d
Nov 26 16:10:23 L00301C002075 kubelet[3996]: E1126 16:10:23.248173    3996 kubelet.go:2103] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

i tried to follow this solution but it wasn't working for me

Coredns in pending state in Kubernetes cluster

does anyone have further suggestions?

While the output of status kubelet

That must be exactly what it says. Have you tried to install a CNI plugin? Which one? If no, start here. https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network. Than you'll need to choose a plugin. Usually Flannel is the best option for beginners. https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network — Olesya Bolobova, Nov 27 '20 at 01:50

score 0 · Answer 1 · answered Nov 27 '20 at 10:35

You should boostrap your cluster with a Network CNI, for example Calico which is officially supported by Kubernetes.

First run kubeadm init with correct pod-network-cidr:

sudo kubeadm init --pod-network-cidr=192.168.0.0/16 --<additional-flags>

After cluster is deployed run following commands:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Once done you can install Calico:

kubectl create -f https://docs.projectcalico.org/manifests/tigera-operator.yaml
kubectl create -f https://docs.projectcalico.org/manifests/custom-resources.yaml

When calico pods are successfully deployed CoreDNS will start autimatically.

Then you can add nodes to your cluster using kubeadm join command.

Coredns in pending state in Kubernetes cluster v1.19.4

1 Answers1