Kubernetes Cheatsheet¶

A quick-lookup kubectl reference — grouped tables instead of prose. For deeper explanations and YAML examples, see Docker & Kubernetes.

🧭 Context & Namespace¶

Command	What it does
`kubectl config get-contexts`	List available clusters
`kubectl config use-context <ctx>`	Switch cluster
`kubectl config set-context --current --namespace=<ns>`	Set default namespace for current context
`kubectl get ns`	List namespaces

Command	What it does
`kubectl get pods -o wide`	Pods with node/IP
`kubectl get all -n <ns>`	Everything in a namespace
`kubectl describe pod <pod>`	Full detail + recent Events
`kubectl get events --sort-by=.metadata.creationTimestamp \\| tail`	Recent cluster events, oldest first
`kubectl top pods` / `kubectl top nodes`	Live CPU/memory usage (needs metrics-server)
`kubectl get pods --field-selector=status.phase!=Running`	Pods not in a healthy phase

Command	What it does
`kubectl logs -f <pod>`	Follow logs
`kubectl logs <pod> -c <container>`	Logs from one container in a multi-container pod
`kubectl logs <pod> --previous`	Logs from the container's last crash
`kubectl exec -it <pod> -- sh`	Shell into a pod
`kubectl cp <pod>:/path ./local`	Copy a file out of a pod
`kubectl port-forward svc/<svc> 8080:80`	Tunnel a Service to localhost

Command	What it does
`kubectl apply -f deploy.yaml`	Create/update from manifest
`kubectl rollout status deployment/<name>`	Watch a rollout finish
`kubectl rollout undo deployment/<name>`	Roll back to the previous revision
`kubectl rollout history deployment/<name>`	List revisions
`kubectl scale deployment/<name> --replicas=5`	Manual scale
`kubectl set image deployment/<name> <container>=<image>`	Change image without editing YAML

Command	What it does
`kubectl describe pod <pod>`	Events section explains most scheduling/probe failures
`kubectl get pod <pod> -o jsonpath='{.status.containerStatuses[0].lastState.terminated.reason}'`	Why the last container exit happened
`kubectl debug <pod> -it --image=busybox --target=<container>`	Attach an ephemeral debug container
`kubectl get endpoints <svc>`	Confirm which pods a Service is actually routing to
`kubectl auth can-i <verb> <resource> --as=<user>`	Check RBAC permissions

Common describe findings and what they mean:

Event/State	Usual cause
`ImagePullBackOff`	Wrong image tag, private registry auth missing
`CrashLoopBackOff`	App exits immediately — check `logs --previous`
`0/1 Running` (never Ready)	Readiness probe failing — see the probes lab
`Pending` + no node events	Insufficient CPU/memory on any node, or an unsatisfied nodeSelector/affinity
`OOMKilled`	Container hit its memory limit

wideyamljsonpathcustom-columns

kubectl get pods -o wide

kubectl get deployment web -o yaml

kubectl get pods -o jsonpath='{.items[*].metadata.name}'

kubectl get pods -o custom-columns=NAME:.metadata.name,STATUS:.status.phase

Command	What it does
`kubectl create configmap app-cfg --from-literal=ENV=prod`	Create a ConfigMap from a literal
`kubectl create secret generic app-secret --from-literal=DB_PASSWORD=change-me`	Create a Secret from a literal
`kubectl get secret <name> -o jsonpath='{.data.<key>}' \\| base64 -d`	Decode a Secret value

Command	What it does
`kubectl delete pod <pod>`	Delete one pod (Deployment recreates it)
`kubectl delete -f deploy.yaml`	Delete everything defined in a manifest
`kubectl delete pods --field-selector=status.phase=Failed -A`	Sweep failed pods cluster-wide
`kubectl get pods -A -o wide \\| grep Evicted`	Find evicted pods (usually node pressure)

kubectl describe before kubectl logs — the Events section usually tells you which of the two you actually need to read next.