March 02, 2020
Kubernetes Basics
Using minikube to create a single node cluster
Check if minikube is installed
minikube version
Start the cluster
minikube start
minikube status
minikube can download the appropriate version of kubectl
minikube kubectl -- get pods -A
Check if kubectl is installed
kubectl version
Check cluster details
kubectl cluster-info
View nodes in the cluster
kubectl get nodes
Deploy an app
kubectl create deployment kubernetes-bootcamp --image=gcr.io/google-samples/kubernetes-bootcamp:v1
List your deployment
kubectl get deployments
Check existing pods
kubectl get pods
kubectl get pods -o wide
Describe pods
kubectl describe pods
Check logs of a container running in pod
kubectl logs $POD_NAME
Execute command directly inside container running in a pod
kubectl exec $POD_NAME env
Start a bash session in a pod container
kubectl exec -ti $POD_NAME bash
To close your container connection type exit.
List current services from your cluster
kubectl get services
Create a new service and expose it to external traffic with NodePort as paramter
kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080
Describe a service
kubectl describe services/kubernetes-bootcamp
Test your app on the externally exposed port
curl $(minikube ip):$NODE_PORT
Note: You can also run following command to check your deployment minikube will start the tunnel for your service and open it in default browser…
minikube service kubernetes-bootcamp
Query list of pods using label
kubectl get pods -l run=kubernetes-bootcamp
Query list of services using label
kubectl get services -l run=kubernetes-bootcamp
Apply a new label to the object
kubectl label pod $POD_NAME app=v1
Deleting a service
kubectl delete service -l run=kubernetes-bootcamp
Scale up the service
kubectl scale deployments/kubernetes-bootcamp --replicas=4
Scale down the service
kubectl scale deployments/kubernetes-bootcamp --replicas=2
Rolling update, Update the image of your application
kubectl set image deployments/kubernetes-bootcamp kubernetes-bootcamp=jocatalin/kubernetes-bootcamp:v2
Confirm an update
kubectl rollout status deployments/kubernetes-bootcamp
Rollback an update
kubectl rollout undo deployments/kubernetes-bootcamp
Delete a deployment
kubectl delete deployment kubernetes-bootcamp
Stop minikube
minikube stop