kubectl Commands

# install (macOS)
brew install kubectl

# verify
kubectl version --client

# kubeconfig location (default)
~/.kube/config

# merge configs
KUBECONFIG=~/.kube/config:~/other-cluster.yaml kubectl config view --flatten > ~/.kube/config

kubectl config get-contexts                          # list contexts
kubectl config current-context                       # show active context
kubectl config use-context my-cluster                # switch context
kubectl config set-context --current --namespace=dev # set default namespace
kubectl config delete-context old-cluster            # remove context
kubectl config rename-context old new                # rename

kubectl get <resource>                   # list in current namespace
kubectl get <resource> -n staging        # specific namespace
kubectl get <resource> -A                # all namespaces
kubectl get <resource> -o wide           # extra columns (IP, node, etc.)
kubectl get <resource> -o yaml           # full YAML
kubectl get <resource> -o json           # full JSON
kubectl get <resource> -o name           # just resource/name pairs
kubectl get <resource> --watch           # stream updates
kubectl get <resource> --show-labels     # include labels column

# extract a specific field
kubectl get pod my-pod -o jsonpath='{.status.podIP}'
kubectl get nodes -o jsonpath='{.items[*].metadata.name}'
kubectl get svc -o jsonpath='{.items[*].spec.clusterIP}'

# custom columns
kubectl get pods -o custom-columns='NAME:.metadata.name,STATUS:.status.phase,NODE:.spec.nodeName'

# sort by field
kubectl get pods --sort-by='.metadata.creationTimestamp'
kubectl get pods --sort-by='.status.startTime'

kubectl apply -f manifest.yaml           # create or update (idempotent)
kubectl apply -f ./dir/                  # apply all YAML files in a directory
kubectl apply -f https://url/file.yaml   # from URL
kubectl apply -k ./kustomize/            # apply Kustomize overlay

kubectl create -f manifest.yaml          # create only (errors if exists)
kubectl replace -f manifest.yaml         # replace (must exist)

kubectl delete -f manifest.yaml          # delete what the manifest describes
kubectl delete pod my-pod                # delete by name
kubectl delete pods --all -n staging     # delete all pods in namespace
kubectl delete all --all -n staging      # delete all common resources
kubectl delete pod my-pod --grace-period=0 --force   # immediate

kubectl describe pod my-pod              # events, state, probes
kubectl describe node my-node            # capacity, conditions, pods
kubectl describe deployment api          # replica history, events

kubectl logs my-pod                      # stdout of first container
kubectl logs my-pod -c sidecar           # specific container
kubectl logs my-pod --previous           # previous (crashed) container
kubectl logs my-pod --tail=100           # last 100 lines
kubectl logs my-pod --since=1h           # since duration
kubectl logs my-pod -f                   # follow (stream)
kubectl logs -l app=api --all-containers # logs for all matching pods

kubectl exec -it my-pod -- bash          # interactive shell
kubectl exec my-pod -- env               # run one-off command
kubectl exec -it my-pod -c sidecar -- sh # exec into specific container

kubectl cp my-pod:/app/log.txt ./log.txt  # copy from pod
kubectl cp ./config.yaml my-pod:/etc/app/ # copy to pod

kubectl port-forward pod/my-pod 8080:80
kubectl port-forward svc/api 8080:80
kubectl port-forward deployment/api 8080:80

kubectl scale deployment api --replicas=5
kubectl set image deployment/api api=myrepo/api:v2
kubectl set env deployment/api LOG_LEVEL=debug
kubectl set resources deployment/api -c api --limits=cpu=1,memory=512Mi
kubectl label pod my-pod version=v2
kubectl label pod my-pod version-          # remove label
kubectl annotate deployment api team=backend
kubectl patch deployment api -p '{"spec":{"replicas":3}}'
kubectl patch svc api --type=merge -p '{"spec":{"type":"LoadBalancer"}}'

kubectl rollout status deployment/api     # watch progress
kubectl rollout history deployment/api    # list revisions
kubectl rollout undo deployment/api       # roll back one revision
kubectl rollout undo deployment/api --to-revision=3
kubectl rollout pause deployment/api
kubectl rollout resume deployment/api
kubectl rollout restart deployment/api    # rolling restart

kubectl get nodes
kubectl get nodes -o wide                  # OS, kernel, container runtime
kubectl describe node my-node
kubectl cordon my-node                     # mark unschedulable (no new pods)
kubectl uncordon my-node                   # re-enable scheduling
kubectl drain my-node --ignore-daemonsets --delete-emptydir-data
kubectl top nodes                          # CPU/memory (needs metrics-server)
kubectl top pods                           # per-pod CPU/memory
kubectl top pods --containers              # per-container

# one-shot debug container
kubectl run debug --image=busybox --rm -it --restart=Never -- sh

# curl from inside the cluster
kubectl run curl --image=curlimages/curl --rm -it --restart=Never -- curl http://api/health

# dns lookup
kubectl run dnsutils --image=registry.k8s.io/e2e-test-images/jessie-dnsutils:1.3 \
  --rm -it --restart=Never -- nslookup api.production.svc.cluster.local

kubectl explain pod
kubectl explain pod.spec
kubectl explain pod.spec.containers.resources
kubectl explain deployment.spec.strategy

# install krew plugin manager
brew install krew

kubectl krew install ctx       # kubectx — fast context switching
kubectl krew install ns        # kubens — fast namespace switching
kubectl krew install neat       # clean up noisy YAML output
kubectl krew install tree       # show owner-reference tree
kubectl krew install stern      # multi-pod log tailing