CKA certification cluster troubleshooting questions

1. Very important things to remember. 

The string here and the path are very important. 
Always check the logs of kublet service. 

If the api server connection timeout then make sure that you are not missing anything in firewall. 
Make sure to check the logs to see the process is not complaining about it. Make sure path provides for all the configuration in config.yaml is correct and there is no syntax error. The logs will print details if there is any syntax error. 

[root@master ~]# cat /var/lib/kubelet/config.yaml | grep static
staticPodPath: /etc/kubernetes/manifests

2. POD and service DNS is not resolving in kubernetes.

Make sure that the busybox that you are trying to resolve it from is correct version. It should be following as per kubernetes doc.

kubectl apply -f https://k8s.io/examples/admin/dns/busybox.yaml

I was running older version of busybox that made pod DNS not working.

Pod DNS is:

10-3-3-3.<your_namespace>.pod.cluster.local

Service DNS is:

servicename.s<your_namespace>.svc.cluster.local