k8s cheatsheet

Use kubectx for switching between contexts / namespaces
For all commands should specify --namespace <NAMESPACE> or --all-namespaces or kubectl will use default namespace
kubectl auth can-i create deployments --namespace <NAMESPACE> --> Check deployment permission
General grammar: kubectl <verb> <noun> [options]
https://www.digitalocean.com/community/tutorials/how-to-inspect-kubernetes-networking
kubectl get pods --namespace=<NAMESPACE> -o wide | grep <SERVICE> --> Get all pods running a service
kubectl exec -it <POD> --namespace <NAMESPACE> -- /bin/bash --> Open shell inside some pod. Can also do other commands
Port forwarding to access service from localhost (Helm chart message upon successful deployment)

1. Get the application URL by running these commands:
  export POD_NAME=$(kubectl get pods --namespace <NAMESPACE> -l "app.kubernetes.io/name=wm-server,app.kubernetes.io/instance=wm-server" -o jsonpath="{.items[0].metadata.name}")
  export CONTAINER_PORT=$(kubectl get pod --namespace <NAMESPACE> $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
  echo "Visit http://127.0.0.1:8080 to use your application"
  kubectl --namespace <NAMESPACE> port-forward $POD_NAME 8080:$CONTAINER_PORT

kubectl get pod $(kubectl get pods --namespace api | grep <SERVICE> | awk '{print $1}') --namespace api --> Check pod status after deploying service
Prepare some swiss army debugging container. Examples: netshoot , cdebug
Official cheatsheet
Debug running containers
Debugging
- kubectl exec -it <pod_name> [-c container_name] -- /bin/bash --> Run /bin/bash in chosen pod / container
- kubectl attach -it <pod_name> [-c container_name] --> Attach to the chosen pod / container to stream output
- kubectl run -it busybox --image=busybox --> Spin up a new busybox debug container
- kubectl debug
- others techniques

memoryonrepeat/k8s-cheatsheet.md