In this lecture we will see different ways of troubleshooting control plane failures.
We start by checking the status of the nodes in the cluster. See if they are all healthy.
Then check the status of the PODs running on the cluster.
If we had control plane components deployed as pods, in case of a cluster deployed with the kubeadm
tool, then we can check to make sure that the pods in the kube-system namespace are running. Or else
if the control plane components are deployed as services as in our case, then check the status of the
services such as the kube-apiserver, controller-manager and scheduler on the master nodes. And the
kubelet and kube-proxy service on the worker nodes
Next
check the logs of the control plane components. Again, in case of kubeadm, use the kubectl logs command
to view the logs of pods hosting the control plane components. In case of services configured natively
on the master nodes, view the service logs using the host’s logging solution. In our case we could use
the journalctl utility to view the kube-apiservers logs.
This should be a good start.
For more tips, refer to the Kubernetes documentation page for Troubleshooting Clusters.
This will help in the upcoming practice test as well as in the exam.