Kubernetes troubleshooting

Application Failure

Check service

#curl http://<appname>

#kubectl describe service <service name>

Check pod

#kubectl get pod

#kubectl describe pod <pod name>

#kubectl logs <pod name> 

https://kubernetes.io/docs/tasks/debug-application-cluster/debug-application/

Control Plane Failure

Use kubeadm setup cluster

#kubectl get pod -n kube-system

#kubectl logs <pod name> -n kube-system

Deploy as service

#service kube-apiserver status

#service kube-controller-manager status

#service kube-scheduler status

#service kubelet status

#service kube-proxy status

#journalctl -u kube-apiserver

https://kubernetes.io/docs/tasks/debug-application-cluster/debug-cluster/

Work Node Failure

#kubectl get node

#kubectl describe node <node name>

ssh to node 

#service kubelet status

#systemctl start kubelet.service

#journalctl -u kubelet

Check kubelet config file

/var/lib/kubelet/config.yaml

Check certificate

#openssl x509 -in <certificate crt file> -text

Network Failure