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Vlad-Raul Guran
Vlad-Raul Guran

Posted on Originally published at vladguran.github.io

kubectl Troubleshooting & Daily Commands Cheat Sheet

#kubernetes #kubectl #devops #sre

Production-grade triage, debugging, and recovery with kubectl, targeting kubectl / Kubernetes v1.31+.

Quick Reference

Task Command
Wide pod status kubectl get pods -o wide -n <ns>
Full object state and events kubectl describe pod <pod>
Recent warnings kubectl events -n <ns> --types=Warning
Logs from the crashed container kubectl logs <pod> -c <ctr> --previous
Tail logs across a label kubectl logs -l app=web --prefix --since=15m -f
Shell into a container kubectl exec -it <pod> -c <ctr> -- sh
Ephemeral debug container kubectl debug -it <pod> --image=busybox:1.36 --target=<ctr>
Node shell kubectl debug node/<node> -it --image=busybox:1.36
Resource usage kubectl top pod -n <ns> --sort-by=memory
Rollout progress kubectl rollout status deploy/<name> --timeout=5m
Roll back kubectl rollout undo deploy/<name>
Local tunnel kubectl port-forward svc/<svc> 8080:80
RBAC check kubectl auth can-i <verb> <resource> --as=<user>
Preview changes kubectl diff -f <file>.yaml
Wait for readiness kubectl wait --for=condition=Ready pod -l app=web --timeout=120s

Core Patterns

1. Triage a failing pod

Walk from coarse to fine: status, then conditions and events, then logs from the previous container instance. Most crash causes appear in describe before you read any logs.

NS=prod; POD=web-7d9f8c6b5-x2k4p
kubectl get pod $POD -n $NS -o wide          # STATUS, RESTARTS, NODE, IP
kubectl describe pod $POD -n $NS             # Conditions, State/Last State, Events
kubectl events -n $NS --for pod/$POD         # events scoped to this pod
kubectl logs $POD -n $NS --all-containers --previous --tail=200
kubectl get pod $POD -n $NS -o yaml          # full spec plus status
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2. Decode why a container died

lastState.terminated holds the reason and exit code. Exit code 137 means SIGKILL, usually OOMKilled. Exit code 143 means SIGTERM. Exit code 1 means an application error.

kubectl get pod $POD -n $NS -o jsonpath='{range .status.containerStatuses[*]}{.name}{"\t"}{.restartCount}{"\t"}{.lastState.terminated.reason}{"\t"}{.lastState.terminated.exitCode}{"\n"}{end}'

# Waiting reasons: CrashLoopBackOff, ImagePullBackOff, CreateContainerConfigError
kubectl get pod $POD -n $NS -o jsonpath='{.status.containerStatuses[*].state.waiting}'

# Pods with the most restarts, cluster-wide
kubectl get pods -A --sort-by='.status.containerStatuses[0].restartCount' | tail -15
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This is the free part. The full kubectl Troubleshooting & Daily Commands Cheat Sheet (production commands, best practices, common pitfalls and a debugging checklist on 2–4 dense pages) is available as a PDF, pay what you want: https://guranova.gumroad.com/l/wktiwb

More sheets: https://vladguran.github.io/dev-cheatsheets/

This article was written with AI assistance.

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