Quick Cheat Sheet

Notes from the things I'm working on at the moment.

Quick Cheat Sheet

kubectl Common Commands

Connecting kubectl to a new cluster:

  • On AWS, aws eks –region update-kubeconfig --name
  • All other cases: https://docs.aws.amazon.com/eks/latest/userguide/create-kubeconfig.html

Get information about the cluster

  • kubectl cluster-info

Get information about the nodes:

  • kubectl get nodes
  • kubectl get nodes -o wide

Get information about the pods:

  • kubectl get pods
  • kubectl get pods --namespace kube-system

Get information about the pods:

  • kubectl get pods --namespace kube-system -o wide
  • kubectl get all —all-namespaces | less

Get All the API Resources for Kubernetes

  • kubectl api-resources | head -n 10

You can get kubectl to explain more details about resources by running:

  • kubectl explain <resource-name> | more
  • kubectl explain pod | more
  • kubectl explain pod.spec | more
  • kubectl explain pod.spec.containers | more

Get detailed information about the master or nodes:

  • get all available nodes: kubectl get nodes

  • kubectl describe nodes <master-node>
  • kubectl describe nodes <slave-node>

Deployments:

Imperative Deployments - One time runs, but not a sustainable way to do things with K8s

  • kubectl create deployment nginx --image=nginx
  • kubectl run nginx --image=nginx
  • Creates a deployment by default:
    • kubectl create deployment hello-world —image=gcr.io/google-samples/hello-app:1.0
    • kubectl run hello-world --image=gcr.io/google-samples/hello-app:1.0
  • Deploy to a single pod:
    • kubectl run hello-world-pod --image=gcr.io/google-samples/hello-app:1.0 --generator=run-pod/v1

Declarative:

  • Define our desired state in code and use a manifest to do this
  • kubectl apply -f deployment.yaml (or deployment.json)

Start a process inside a container inside a pod

  • kubectl exec -it hello-world-pod -- /bin/sh

Expose: Export ports to the public world

  • kubectl expose deployment hello-world --port=80 --target-port=8080

Another sample deployment:

kubectl create deployment hello-minikube --image=k8s.gcr.io/echoserver:1.4 kubectl expose deployment hello-minikube --type=NodePort --port=8080

kubectl port-forward service/hello-minikube 7080:8080