Containers & Orchestration
Kubernetes orchestrates containerized applications at scale.
On this page
Use this page for fast recall. Use Full documentation when you want the complete end-to-end path.
A simple 5-step flow you can follow when using Kubernetes in real work.
1) Setup
Install/run the tool and confirm version. Create a minimal config.
2) Small change
Do one small action end-to-end to prove the workflow.
3) Validate
Check output, logs, and status. Catch mistakes early.
4) Automate
Convert it into a repeatable script or pipeline step.
5) Productionize
Add safety: secrets, rollback, observability, and docs.
These are practical sequences you can copy into your own checklist or runbook.
Goal: Identify why the container is restarting and fix the real root cause.
- Describe the pod and read events (probe failures, image pull, OOM).
- Read logs (use `-c` for multi-container pods).
- Check environment variables and mounted config/secrets.
- Validate readiness/liveness probes.
- Roll forward a fix, or rollback safely if needed.
- Pods
- Deployments
- Services
Learning path (high-level):
- Core objects
- Production deployments
- Troubleshooting
Check cluster
Command
kubectl cluster-infoApply manifest
Command
kubectl apply -f deployment.yamlWatch pods
Command
kubectl get pods -wShort descriptions and practical intent. Search, filter, copy, and reuse.
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kubectl version --clientShow kubectl version.
kubectl config get-contextsList contexts.
kubectl config current-contextShow current context.
kubectl config use-context <ctx>Switch cluster context.
kubectl get nsList namespaces.
kubectl get all -n defaultList core resources in namespace.
kubectl get pods -n <ns> -o widePods with nodes/IPs.
kubectl get deploy -n <ns>List deployments.
kubectl get svc -n <ns>List services.
kubectl apply -f k8s.yamlApply manifests (create/update).
kubectl delete -f k8s.yamlDelete resources from manifest.
kubectl rollout status deploy/<name> -n <ns>Check rollout progress.
kubectl rollout history deploy/<name> -n <ns>Show rollout history.
kubectl rollout undo deploy/<name> -n <ns>Rollback to previous revision.
kubectl describe pod <pod> -n <ns>Detailed pod info and events.
kubectl get events -n <ns> --sort-by=.metadata.creationTimestampNamespace events (time-sorted).
kubectl logs <pod> -n <ns>Read pod logs.
kubectl logs -f <pod> -n <ns>Follow logs.
kubectl logs <pod> -c <container> -n <ns>Logs for a specific container.
kubectl exec -it <pod> -n <ns> -- shOpen pod shell.
kubectl port-forward svc/<svc> 8080:80 -n <ns>Forward local port to service.
kubectl set image deploy/<name> <container>=repo/img:tag -n <ns>Update container image.
kubectl scale deploy/<name> --replicas=3 -n <ns>Scale deployment.
kubectl top pods -n <ns>Pod CPU/mem (metrics server).
kubectl top nodesNode CPU/mem (metrics server).
Small blocks you can drop into your terminal, config, or runbook.
Common triage sequence
bash
kubectl get pods -n <ns>
kubectl describe pod <pod> -n <ns>
kubectl logs <pod> -n <ns> --tail=200When things break, follow this order to stay calm and move fast.
- If pods are Pending: check node capacity, taints/tolerations, and PVC binding events.
- If ImagePullBackOff: verify image name/tag, registry access, and imagePullSecrets.
- If 503/traffic issues: check Service selectors, endpoints, and readiness probes.
- If rollouts flap: check probes, resource limits, and startup time.
The common mistakes that slow people down when using Kubernetes.
- Debugging only with `kubectl get` and ignoring `describe`/events.
- Missing resource requests/limits and breaking node stability.
- No readiness/liveness probes leading to broken rollouts.
Do these tasks in order. You will feel the tool instead of just reading about it.
- Deploy a simple app, expose it with a Service, and port-forward to test locally.
- Break the deployment (wrong image) and debug using `describe`, `events`, and `logs`.
- Practice a rollback using rollout history and undo.
Use these to test if you truly understand the basics (and can explain them clearly).
- Explain Deployments, ReplicaSets, and Pods.
- How do you debug CrashLoopBackOff?
- What’s the difference between ClusterIP, NodePort, and LoadBalancer services?