I recently did a fresh installation of Kubernetes cluster of one master and one worker node. However coredns pods show 0/1 in ready column.
Cluster information:
Kubernetes version: v1.18.4
Cloud being used: (put bare-metal if not on a public cloud) : Bare metal
Installation method: Using Kubeadm
Host OS: CentOS Linux release 8.2.2004 (Core)
CNI and version: docker.io/cilium/cilium:v1.8.0
CRI and version: Docker version 19.03.12, build 48a66213fe
]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
dw-incoming-ehsw.wolfden.wolfmedical.com Ready master 92m v1.18.4
dw-mirth-srv01w.wolfden.wolfmedical.com Ready 89m v1.18.4
[root@dw-incoming-ehsw ~]# kubectl -n kube-system get pods
NAME READY STATUS RESTARTS AGE
cilium-ndrrd 1/1 Running 0 91m
cilium-operator-754dd76d85-6lvfr 1/1 Running 0 92m
cilium-v746z 1/1 Running 0 92m
coredns-66bff467f8-lg7k5 0/1 Running 0 13m
coredns-66bff467f8-rg7ps 0/1 Running 0 29m
Logs show that readiness probe fails:
Events:
Type Reason Age From Message
Normal Started 30m kubelet, dw-mirth-srv01w.wolfden.wolfmedical.com Started container coredns
Warning Unhealthy 35s (x181 over 30m) kubelet, dw-mirth-srv01w.wolfden.wolfmedical.com Readiness probe failed: HTTP probe failed with statuscode: 503
Added port 8080 and 8081 to INPUT tables, still not fixed. I did see somewhere in coredns logs: No route to host error
[ERROR] plugin/errors: 2 8223092739186447773.3763193590245604957. HINFO: read udp 10.0.1.121:57509->10.27.122.7:53: read: no route to host