kubectl Troubleshooting Commands for Kubernetes CKA

Troubleshooting

Troubleshooting in Kubernetes involves identifying and resolving issues with the various resources and workloads running in the cluster. Here are the imperative commands that are particularly useful for troubleshooting:

Logs

Fetches and displays the logs of a specific pod, which is useful for debugging and understanding the behavior of the applications running in the pod.

kubectl logs <pod-name>

Get Logs of a Specific Container

Fetches and displays the logs of a specific container within a pod.

kubectl logs <pod-name> -c <container-name>

Stream Logs

Streams the logs of a pod, useful for monitoring logs in real-time.

kubectl logs -f <pod-name>

Events

Displays detailed information about a specific resource, including events associated with it.

kubectl describe <resource> <name>

List Events

Lists all events in the current namespace, providing an overview of what has happened in the cluster.

kubectl get events

Exec into Container

Executes a command in a container within a pod, allowing interactive access (such as a bash shell) for troubleshooting.

kubectl exec -it <pod-name> -- /bin/bash

Execute a Command in a Specific Container

Executes a command in a specific container within a pod, useful when dealing with multi-container pods.

kubectl exec -it <pod-name> -c <container-name> -- /bin/bash

Port Forwarding

Forwards a local port to a port on a pod, allowing access to a pod's service on the local machine.

kubectl port-forward <pod-name> <local-port>:<remote-port>

Port Forwarding for a Service

Forwards a local port to a port on a service, useful for accessing a service locally.

kubectl port-forward svc/<service-name> <local-port>:<remote-port>

Describe Pod

Displays detailed information about a pod, including its status, events, and resource usage.

kubectl describe pod <pod-name>

Describe Node

Displays detailed information about a node, which can help diagnose node-specific issues.

kubectl describe node <node-name>

Get Pod Info

Retrieves detailed YAML representation of a pod, useful for understanding its configuration and current state.

kubectl get pod <pod-name> -o yaml

Get Node Info

Retrieves detailed YAML representation of a node, useful for understanding its configuration and current state.

kubectl get node <node-name> -o yaml

Debugging a Pod with Debug Container

Attaches a debug container to a running pod for in-depth troubleshooting.

kubectl debug pod/<pod-name> -it --image=<debug-image> --target=<container-name>

View System Logs with journalctl

Fetches and displays logs for a specific system service managed by systemd.

journalctl -u <service-name>

Stream System Logs with journalctl

Streams logs for a specific system service in real-time.

journalctl -u <service-name> -f

View Logs for All Services

Displays the systemd logs for all services with detailed debugging information.

journalctl -xe