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Setting up the environment

  • place config files (credentials) in ~/.kube/
  • Install kubectl https://kubernetes.io/docs/tasks/tools/install-kubectl/
  • set the KUBECONFIG environment variable to the desired config file (ie. set -x KUBECONFIG ~/.kube/staging-edit.conf) (alternatively use --kubeconfig flag to point to the config)
  • run kubectl version to confirm that things are set up properly, `run kubectl get pods -n to confirm that you are able to access the cluster for the corresponding credential

General Kubernetes Telemetry

(after setting your KUBECONFIG)

Listing Resources

kubectl get pods                       # List all pods in the current namespace
kubectl get secrets
kubectl get services
kubectl get sts
kubectl describe pods <pod-name>       # Print a detailed description of the specified pod
kubectl describe sts/<sts-name>

Interacting with pods

Running commands

kubectl exec <pod-name> -it /bin/sh                           # start an interactive shell in the pod (if one container -- add '-c <container-name> if multi-container case)
kubectl exec <pod-name> env                                   # check pod environment variables
kubectl exec <pod-name> -- <command>                          # run command in pod (single container)

Logs

kubectl logs <pod-name>                                       # dump pod logs (stdout)
kubectl logs -f <pod-name>                                    # stream pod logs (stdout)
kubectl logs <pod-name> -p                                    # dump pod logs (stdout) for a previous instantiation of a container
kubectl exec <pod-name> -- tail -f <path to container logs>   # stream container logs
kubectl cp <pod-name>:path/to/app.log .                       # copy log life to local directory

Port forward/REPL

kubectl port-forward <pod-name> <port>                        # listen on port <port> locally, forwarding to <port> in the pod
kubectl port-forward <pod-name> local-port:pod-port           # forward a port to a specified local port

Restarting apps

The number of running pods is controlled by the "replicas" field in the app's statefulset. For our applications this will always be set to 1. To restart an application, set the replicas to 0 then back to 1.

kubectl scale --replicas=0 sts <sts name>
kubectl scale --replicas=1 sts <sts name>

Other cheatsheets