Docker to k8s Cheat Sheet

The full concept map. When lost, find the Docker thing you know and look right.

Concepts

Docker concept	Kubernetes equivalent
docker run	Pod (lowest unit, wraps 1+ containers)
docker compose service	Deployment
docker compose file	A set of YAML manifests (or a Helm chart / Kustomize base)
compose project	Namespace
compose networks / service names	Service (ClusterIP) + cluster DNS
-p 8080:80	Service (NodePort/LoadBalancer) or Ingress
named volumes	PersistentVolumeClaim (+ StorageClass)
bind mounts	hostPath (avoid) or ConfigMap mounts for config files
.env / environment:	ConfigMap + Secret
restart: always	Built-in - controllers reschedule pods
healthcheck:	Liveness/readiness/startup probes
depends_on	Nothing - readiness probes + retry logic in the app
docker run from cron	Job / CronJob
deploy.resources	resources.requests / resources.limits
swarm replicas	Deployment replicas + HorizontalPodAutoscaler

Commands

Docker command	kubectl equivalent
docker ps	kubectl get pods
docker inspect <c>	kubectl describe pod <p>
docker logs -f <c>	kubectl logs -f <p>
docker exec -it <c> sh	kubectl exec -it <p> -- sh
docker compose up -d	kubectl apply -f .
docker compose down	kubectl delete -f .
docker stats	kubectl top pods (needs metrics-server)
docker compose restart x	kubectl rollout restart deployment/x

Failure states quick reference

State	Most common cause
ImagePullBackOff	Tag typo, private registry auth, missing image
CrashLoopBackOff	App dies on boot - check logs --previous
Pending	No node with enough resources, or PVC unbound
OOMKilled	Memory limit too low (or a real leak)
Ready 0/1	Readiness probe failing