I have a ubuntu 16.04 running in virtual box. I installed Kubernetes on it as a single node using kubeadm.
But coredns pods are in Crashloopbackoff state.
All other pods are running.
Single interface(enp0s3) - Bridge Network
Applied calico using kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml
output on kubectl describe pod:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 41m default-scheduler Successfully assigned kube-system/coredns-66bff467f8-dxzq7 to kube
Normal Pulled 39m (x5 over 41m) kubelet, kube Container image "k8s.gcr.io/coredns:1.6.7" already present on machine
Normal Created 39m (x5 over 41m) kubelet, kube Created container coredns
Normal Started 39m (x5 over 41m) kubelet, kube Started container coredns
Warning BackOff 87s (x194 over 41m) kubelet, kube Back-off restarting failed containerCommented below line in /etc/resolv.conf (Host machine) and delete the coredns pods in kube-system namespace. <br> New pods came in running state :)
I did a kubectl logs <coredns-pod> and found error logs below and looked in the mentioned link
As per suggestion, added resolv.conf = /etc/resolv.conf at the end of /etc/kubernetes/kubelet/conf.yamland recreated the pod.
kubectl logs coredns-66bff467f8-dxzq7 -n kube-system
.:53 [INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7 CoreDNS-1.6.7 linux/amd64, go1.13.6, da7f65b [FATAL] plugin/loop: Loop (127.0.0.1:34536 -> :53) detected for zone ".", see coredns.io/plugins/loop#troubleshooting. Query: "HINFO 8322382447049308542.5528484581440387393."
root@kube:/home/kube#