Node troubleshooting in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What command shows the status of all nodes in a Kubernetes cluster?

Use kubectl get nodes to see the status, roles, and age of all nodes in the cluster.

beginner

How can you describe a specific node to get detailed information?

Use kubectl describe node <node-name> to get detailed info like conditions, capacity, and events related to that node.

intermediate

What does it mean if a node is in 'NotReady' state?

A 'NotReady' node means Kubernetes cannot schedule pods on it because it failed health checks or lost connection.

intermediate

Which logs are useful to check when troubleshooting node issues?

Check the kubelet logs on the node using <code>journalctl -u kubelet</code> or system logs to find errors causing node problems.

intermediate

How can you safely remove a problematic node from the cluster?

First, drain the node with kubectl drain <node-name> --ignore-daemonsets to move pods away, then delete it with kubectl delete node <node-name>.

Which command lists all nodes and their status in Kubernetes?

A kubectl get nodes

B kubectl get pods

C kubectl describe pods

D kubectl get services

kubectl get nodes shows all nodes and their status.

What does the 'NotReady' status on a node indicate?

A Node is healthy and ready

B Node is unreachable or failing health checks

C Node is running pods normally

D Node is being deleted

'NotReady' means the node is unreachable or failing health checks.

How do you get detailed information about a node's conditions and events?

A kubectl describe node <node-name>

B kubectl get nodes

C kubectl logs node

D kubectl get pods

kubectl describe node <node-name> shows detailed info about the node.

Which logs are most helpful to check when a node has issues?

A Pod logs

B API server logs

C Service logs

D kubelet logs on the node

Kubelet logs on the node help diagnose node problems.

What is the correct order to safely remove a node from a cluster?

A Delete node, then drain it

B Restart node, then delete it

C Drain node, then delete it

D Delete pods, then delete node

Drain the node first to move pods, then delete the node.

Explain the steps you would take to troubleshoot a Kubernetes node that shows 'NotReady' status.

Start by checking status and logs, then move to deeper investigation.

Describe how to safely remove a node from a Kubernetes cluster and why each step is important.

Think about pod safety and cluster health.