Cheat Sheet¶

A cheat sheet for Kubernetes commands.

Kubectl Command¶

Alias¶

alias k=kubectl

Completion¶

Add kubectl auto completion

source <(kubectl completion bash)

Windows¶

Set-Alias -Name k -Value kubectl

Cluster Info¶

Get Clusters¶

kubectl config get-clusters
NAME
docker-for-desktop-cluster
foo

Get Cluster Info¶

kubectl cluster-info
Kubernetes master is running at https://172.17.0.58:8443

Contexts¶

A context is a cluster, namespace and user

Get a list of contexts¶

kubectl config get-contexts

Get the current context¶

kubectl config current-context foo

Switch current context¶

kubectl config use-context docker-desktop

To switch between contexts, you can also install and use kubectx.

Get Commands¶

kubectl get all
kubectl get namespaces
kubectl get configmaps
kubectl get nodes
kubectl get pods
kubectl get rs
kubectl get svc kuard
kubectl get endpoints kuard

Additional switches that can be added to the above commands:

-o wide - Show more information.
--watch or -w - watch for changes.

Namespaces¶

Set default namespace¶

You can set the default namespace for the current context like so

kubectl config set-context $(kubectl config current-context) --namespace=my-namespace

--namespace - Get a resource for a specific namespace

To switch namespaces, you can also install and use kubens

Labels¶

Get pods showing labels¶

kubectl get pods --show-labels

Get pods by label¶

kubectl get pods -l environment=production,tier!=frontend
kubectl get pods -l 'environment in (production,test),tier notin (frontend,backend)'

Describe¶

kubectl describe nodes [id]
kubectl describe pods [id]
kubectl describe rs [id]
kubectl describe svc kuard [id]
kubectl describe endpoints kuard [id]

Delete¶

kubectl delete nodes [id]
kubectl delete pods [id]
kubectl delete rs [id]
kubectl delete svc kuard [id]
kubectl delete endpoints kuard [id]

Force a deletion of a pod without waiting for it to gracefully shut down

kubectl delete pod-name --grace-period=0 --force

Create vs Apply¶

kubectl create can be used to create new resources while kubectl apply inserts or updates resources while maintaining any manual changes made like scaling pods.

--record - Add the current command as an annotation to the resource.
--recursive - Recursively look for yaml in the specified directory.

Create Pod¶

kubectl run kuard --generator=run-pod/v1 --image=gcr.io/kuar-demo/kuard-amd64:1 --output yaml --export --dry-run > kuard-pod.yml
kubectl apply -f kuard-pod.yml

Create Deployment¶

kubectl run kuard --image=gcr.io/kuar-demo/kuard-amd64:1 --output yaml --export --dry-run > kuard-deployment.yml
kubectl apply -f kuard-deployment.yml

Create Service¶

kubectl expose deployment kuard --port 8080 --target-port=8080 --output yaml --export --dry-run > kuard-service.yml
kubectl apply -f kuard-service.yml

Export YAML¶

For New Pod¶

kubectl run my-cool-app —-image=me/my-cool-app:v1 --output yaml --export --dry-run > my-cool-app.yaml

For Existing Object¶

kubectl get deployment my-cool-app --output yaml --export > my-cool-app.yaml

Logs¶

Get logs¶

kubectl logs -l app=kuard

Get logs for previously terminated container¶

kubectl logs POD_NAME --previous

Watch logs in real time¶

kubectl attach POD_NAME

Copy files out of pod¶

Requires tar binary in container

kubectl cp POD_NAME:/var/log .

You can also install and use kail.

Port Forward¶

kubectl port-forward deployment/kuard 8080:8080

Scaling¶

Update replicas¶

kubectl scale deployment nginx-deployment --replicas=10

Autoscaling¶

Set autoscaling config¶

kubectl autoscale deployment nginx-deployment --min=10 --max=15 --cpu-percent=80

Rollout¶

Get rollout status¶

kubectl rollout status deployment/nginx-deployment
Waiting for rollout to finish: 2 out of 3 new replicas have been updated...
deployment "nginx-deployment" successfully rolled out

Get rollout history¶

kubectl rollout history deployment/nginx-deployment
kubectl rollout history deployment/nginx-deployment --revision=2

Undo a rollout¶

kubectl rollout undo deployment/nginx-deployment
kubectl rollout undo deployment/nginx-deployment --to-revision=2

Pause/resume a rollout¶

kubectl rollout pause deployment/nginx-deployment
kubectl rollout resume deploy/nginx-deployment

Examples¶

Pod¶

apiVersion: v1
kind: Pod
metadata:
  name: cuda-test
spec:
  containers:
    - name: cuda-test
      image: "k8s.gcr.io/cuda-vector-add:v0.1"
      resources:
        limits:
          nvidia.com/gpu: 1
  nodeSelector:
    accelerator: nvidia-tesla-p100

Deployment¶

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: my-ns
  labels:
    environment: production
    tier: frontend
  annotations:
    key1: value1
    key2: value2
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:1.7.9
          ports:
            - containerPort: 80

Dashboard¶

Enable proxy

kubectl proxy

Azure Kubernetes Service¶

List of az aks commands

Show Dashboard¶

Secure the dashboard like this. Then run:

az aks browse --resource-group <Resource Group Name> --name <AKS Name>

Get Credentials¶

az aks get-credentials --resource-group <Resource Group Name> --name <AKS Name>

Upgrade¶

Get updates

az aks get-upgrades --resource-group <Resource Group Name> --name <AKS Name>

Get Node Resources Info¶

The Node Feature Discovery operator is a tool for Kubernetes administrators that makes it easy to detect and understand the hardware features and configurations of a cluster's nodes. With this operator, administrators can easily gather information about their nodes that can be used for scheduling, resource management, and more by controlling the life cycle of NFD.