Kubernetes (kubectl)

Contexts, pods, logs, deployments, debugging and port-forward.

Contexts and namespaces

Current context

kubectl config current-context

List contexts

kubectl config get-contexts

Switch context

kubectl config use-context <context>

Default namespace for the current context

kubectl config set-context --current --namespace=<namespace>

Pods in a namespace

kubectl get pods -n <namespace>

Pods with nodes and IPs

kubectl get pods -n <namespace> -o wide

All main resources in a namespace

kubectl get all -n <namespace>

Pod details and events

kubectl describe pod <pod> -n <namespace>

Events sorted by time

kubectl get events -n <namespace> --sort-by=.lastTimestamp

Pods not in Running stateadvanced

kubectl get pods -A --field-selector=status.phase!=Running

Pod resource usage

kubectl top pods -n <namespace>

Follow pod logs

kubectl logs -f <pod> -n <namespace>

Logs of the previous (crashed) container

kubectl logs <pod> -n <namespace> --previous

Logs of all pods in a deployment

kubectl logs -f deployment/<deployment> -n <namespace> --all-containers

Open a shell in a pod

kubectl exec -it <pod> -n <namespace> -- sh

Forward a service port to localhost

kubectl port-forward svc/<k8s_service> 8080:80 -n <namespace>

Temporary pod for network debuggingadvanced

kubectl run debug --rm -it --image=nicolaka/netshoot -n <namespace> -- bash

Apply a manifest

kubectl apply -f manifest.yaml

Restart a deployment

kubectl rollout restart deployment/<deployment> -n <namespace>

Rollout status

kubectl rollout status deployment/<deployment> -n <namespace>

Roll back to the previous version

kubectl rollout undo deployment/<deployment> -n <namespace>

Scale

kubectl scale deployment/<deployment> --replicas=3 -n <namespace>

Decode a secretadvanced

kubectl get secret <k8s_secret> -n <namespace> -o jsonpath='{.data.password}' | base64 -d