Kubernetes Cheat Sheet

Cheet says: k8s is just fancy container orchestration!

Context & Config

kubectl config get-contexts        # List contexts
kubectl config use-context prod    # Switch context
kubectl config current-context     # Current context

Namespace shortcuts
alias k='kubectl'
alias kn='kubectl -n'

Getting Info

kubectl get all                    # Everything in namespace
kubectl get pods -A                # All pods, all namespaces
kubectl get pods -o wide           # More columns
kubectl get pods -w                # Watch mode

kubectl describe pod         # Full details
kubectl logs                  # Container logs
kubectl logs -f               # Follow logs
kubectl logs  -c   # Specific container

Running & Debugging

Quick pod
kubectl run debug --image=busybox -it --rm -- sh

Exec into pod
kubectl exec -it  -- /bin/sh
kubectl exec -it  -c  -- bash

Port forward
kubectl port-forward pod/ 8080:80
kubectl port-forward svc/ 8080:80

Copy files
kubectl cp :/path/file ./local
kubectl cp ./local :/path/file

Creating Resources

From file
kubectl apply -f deployment.yaml
kubectl apply -f ./manifests/

Quick deployments
kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=LoadBalancer

Scale
kubectl scale deployment nginx --replicas=3

Editing & Patching

kubectl edit deployment      # Opens in editor
kubectl set image deployment/ =

Patch
kubectl patch deployment  -p '{"spec":{"replicas":5}}'

Rollout
kubectl rollout status deployment/
kubectl rollout history deployment/
kubectl rollout undo deployment/

Deleting

kubectl delete pod 
kubectl delete -f deployment.yaml
kubectl delete pods --all
kubectl delete namespace     # Careful!

Force delete stuck pod
kubectl delete pod  --grace-period=0 --force

Labels & Selectors

kubectl get pods -l app=nginx
kubectl get pods -l 'env in (prod,staging)'
kubectl label pod  env=prod
kubectl label pod  env-         # Remove label

Resources & Limits

resources:
  requests:
    memory: "64Mi"
    cpu: "250m"
  limits:
    memory: "128Mi"
    cpu: "500m"

Secrets & ConfigMaps

Create secret
kubectl create secret generic my-secret --from-literal=key=value
kubectl create secret generic my-secret --from-file=./secrets/

Create configmap
kubectl create configmap my-config --from-literal=key=value
kubectl create configmap my-config --from-file=config.properties

View (decoded)
kubectl get secret my-secret -o jsonpath='{.data.key}' | base64 -d

Debugging

Events
kubectl get events --sort-by='.lastTimestamp'

Resource usage
kubectl top pods
kubectl top nodes

Explain fields
kubectl explain deployment.spec.replicas

Dry run
kubectl apply -f file.yaml --dry-run=client
kubectl apply -f file.yaml --dry-run=server

Useful Aliases

alias k='kubectl'
alias kgp='kubectl get pods'
alias kgs='kubectl get svc'
alias kgd='kubectl get deployments'
alias kl='kubectl logs'
alias ke='kubectl exec -it'