kubectl

Context and Configuration

Command	Action
kubectl config get-contexts list contexts
kubectl config current-context current
kubectl config use-context NAME switch
kubectl config set-context --current --namespace=NS change ns
kubectl get-contexts -o name machine-readable
kubectl version	client + server version
kubectl cluster-info	cluster endpoints

Tools that streamline this:

• kubectx, kubectx, kubens.

• K9s, TUI for kubectl.

Get / Describe

Command	Action
kubectl get pods	pods in current namespace
kubectl get pods -A	all namespaces
kubectl get pods -o wide extra columns (node, IP)
kubectl get pods -o yaml YAML output
kubectl get pods -o jsonpath='{.items[*].metadata.name}'	custom output
kubectl get all	most resource types
kubectl get deploy,svc,pod multiple types
kubectl describe pod NAME events + details
kubectl get events --sort-by=.metadata.creationTimestamp
kubectl get pods --selector=app=web --watch

Apply / Delete

Command	Action
kubectl apply -f file.yaml apply manifest
kubectl apply -f dir/	directory of manifests
kubectl apply -k overlay/ Kustomize
kubectl delete -f file.yaml
kubectl delete pod NAME	delete by name
kubectl delete pod -l app=web	by selector
kubectl delete pod --all	delete all in namespace
kubectl scale deploy/web --replicas=5
kubectl rollout restart deploy/web
kubectl rollout status deploy/web
kubectl rollout undo deploy/web

Exec / Logs / Port-Forward

Command	Action
kubectl exec -it POD -- bash	shell into pod
kubectl exec -it POD -c CONT -- sh specific container
kubectl logs POD	logs
kubectl logs -f POD	follow
kubectl logs --tail=100 POD
kubectl logs --previous POD previous container
kubectl logs deploy/web	pick any pod from deploy
kubectl port-forward svc/web 8080:80
kubectl port-forward pod/web 8080:80
kubectl cp POD:/path/in/container ./local

Debug

Command	Action
kubectl run debug --rm -it --image=busybox --restart=Never -- sh
kubectl debug POD --image=busybox -it ephemeral debug container
kubectl debug node/NODE --image=busybox -it debug a node
kubectl auth can-i list pods	RBAC check
kubectl auth can-i --list	all my permissions
kubectl top pods	CPU / memory (needs metrics-server)
kubectl top nodes

Resources

Command	Action
kubectl api-resources	list all resource kinds
kubectl api-versions	all groups + versions
kubectl explain pod.spec	schema docs (any field)
kubectl explain pod.spec.containers --recursive

Patching

$ kubectl patch deploy web -p '{"spec":{"replicas":3}}'

$ kubectl patch deploy web --type=json \
  -p='[{"op":"replace","path":"/spec/replicas","value":3}]'

$ kubectl edit deploy web

Useful kubeconfig Tricks

$ KUBECONFIG=~/.kube/config:~/work/kubeconfig kubectl config view --flatten > merged
$ mv merged ~/.kube/config

$ kubectl config set-context --current --namespace=mynamespace

$ kubectl --kubeconfig=/path/to/cfg get pods

JSONPath Examples

$ kubectl get pods -o jsonpath='{.items[*].metadata.name}'

$ kubectl get pods -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].image}{"\n"}{end}'

$ kubectl get nodes -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.status.addresses[?(@.type=="ExternalIP")].address}{"\n"}{end}'