Performing a Rolling Update of an Application in Kubernetes

Create the kubeserve-deployment.yaml file, and add the following YAML to create your deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: kubeserve
spec:
  replicas: 3
  selector:
    matchLabels:
      app: kubeserve
  template:
    metadata:
      name: kubeserve
      labels:
        app: kubeserve
    spec:
      containers:
      - image: linuxacademycontent/kubeserve:v1
        name: app

Use the following command to create the deployment:

kubectl apply -f kubeserve-deployment.yaml --record

Use the following command to verify the deployment was successful:

kubectl rollout status deployments kubeserve

Use the following command to verify the app is at the correct version:

kubectl describe deployment kubeserve

Use the following command to scale up your application to 5 replicas:

kubectl scale deployment kubeserve --replicas=5

Use the following command to verify the additional replicas have been created:

kubectl get pods

Use the following command to create a service for your deployment:

kubectl expose deployment kubeserve --port 80 --target-port 80 --type NodePort

Use the following command to verify the service is present and collect the cluster IP:

kubectl get services

Use this curl loop command to see the version change as you perform the rolling update:

while true; do curl http://<ip-address-of-the-service>; done

Use this command to perform the update (while the curl loop is running):

kubectl set image deployments/kubeserve app=linuxacademycontent/kubeserve:v2 --v 6

Use this command to view the additional ReplicaSet created during the update:

kubectl get replicasets

Use this command to verify all pods are up and running:

kubectl get pods

Use this command to view the rollout history:

kubectl rollout history deployment kubeserve