kubectl config get-contexts
kubectl config use-context stagingList and switch clusters.
kubectl cheat sheet
The kubectl commands you use most, grouped by task. Add -n <namespace> to any command, or -A for all namespaces.
24 entries
Context & config
kubectl config set-context --current --namespace=webDefault namespace for the current context.
kubectl cluster-info
kubectl versionCluster endpoint and versions.
Inspect
kubectl get pods -o wide
kubectl get all -n webList resources (wide adds node and IP).
kubectl get pods -l app=api --watchFilter by label and watch changes.
kubectl describe pod api-7d9c-xk2pEvents, conditions and container states: start debugging here.
kubectl get deploy api -o yamlFull live object as YAML.
kubectl get events --sort-by=.metadata.creationTimestampRecent events in order.
kubectl top pods
kubectl top nodesCPU/memory usage (needs metrics-server).
Logs & shells
kubectl logs -f deploy/api
kubectl logs api-7d9c-xk2p -c sidecar --previousFollow logs; previous crashed container.
kubectl exec -it api-7d9c-xk2p -- shShell inside a container.
kubectl port-forward svc/api 8080:80Reach a service from localhost.
kubectl cp api-7d9c-xk2p:/tmp/dump.txt ./dump.txtCopy files out of a pod.
kubectl debug -it api-7d9c-xk2p --image=busybox --target=apiEphemeral debug container.
Deploy & change
kubectl apply -f k8s/
kubectl diff -f k8s/Apply manifests; preview the change first.
kubectl set image deploy/api api=ghcr.io/me/api:1.4.2Update an image.
kubectl rollout status deploy/api
kubectl rollout history deploy/api
kubectl rollout undo deploy/apiWatch, inspect and roll back.
kubectl rollout restart deploy/apiRestart pods without changing the spec.
kubectl scale deploy/api --replicas=5Scale manually.
kubectl delete pod api-7d9c-xk2pDelete a pod (its Deployment replaces it).
Config & secrets
kubectl create configmap app-cfg --from-file=config.yamlConfigMap from a file.
kubectl create secret generic db --from-literal=PASSWORD=change-meSecret (values are base64, not encrypted, by default).
kubectl get secret db -o jsonpath='{.data.PASSWORD}' | base64 -dRead a secret value.
Minimal manifest
apiVersion: apps/v1
kind: Deployment
metadata:
name: api
spec:
replicas: 2
selector:
matchLabels: { app: api }
template:
metadata:
labels: { app: api }
spec:
containers:
- name: api
image: ghcr.io/me/api:1.4.2
ports: [{ containerPort: 8000 }]
readinessProbe:
httpGet: { path: /health, port: 8000 }
---
apiVersion: v1
kind: Service
metadata:
name: api
spec:
selector: { app: api }
ports: [{ port: 80, targetPort: 8000 }]Deployment + Service; the selector labels must match.
Frequently asked questions
How do I see why a pod is not starting?
Run kubectl describe pod <name> and read the Events at the bottom (image pull errors, failed scheduling, failing probes). Then check kubectl logs <name> --previous for the crashed container’s output.
apply vs create?
kubectl create makes a new object and fails if it exists. kubectl apply creates or updates objects declaratively from files, so it is what you use for manifests kept in git.
What does CrashLoopBackOff mean?
The container starts, exits, and Kubernetes keeps restarting it with increasing delays. The cause is in the container logs (kubectl logs --previous): usually a crash on start-up, a missing config or secret, or a failing command.