Scale Out and Update a Containerized Application on a Kubernetes Cluster
This article will go through the lab to Scale-Out and Update a Containerized Application on a Kubernetes Cluster. This lab is similar to Build and Deploy a Docker Image to a Kubernetes Cluster.
The challenge contains 4 required tasks.
- Check that there is a tagged image in gcr.io for echo-app:v2.
- Echo-app:v2 is running on the Kubernetes cluster.
- The Kubernetes cluster deployment reports 2 replicas.
- The application must respond to web requests with V2.0.0.
Challenge Scenario
You are taking over ownership of a test environment and have been given an updated version of a containerized test application to deploy. Your systems’ architecture team has started adopting a containerized microservice architecture. You are responsible for managing the containerized test web applications. You will first deploy the initial version of a test application, called echo-app to a Kubernetes cluster called echo-cluster in a deployment called echo-web.
Before you get started, open the navigation menu and select Cloud Storage. The last steps in the Deployment Manager script used to set up your environment create a bucket.
Refresh the Storage browser until you see your bucket. You can move on once your Console resembles the following:
Check to make sure your GKE cluster has been created before continuing. Open the navigation menu and select Kubernetes Engine > Clusters.
Continue when you see a green checkmark next to echo-cluster:
To deploy your first version of the application, run the following commands in Cloud Shell to get up and running:
gcloud container clusters get-credentials echo-cluster --zone=us-central1-a
kubectl create deployment echo-web --image=gcr.io/qwiklabs-resources/echo-app:v1
kubectl expose deployment echo-web --type=LoadBalancer --port 80 --target-port 8000
1.Check that there is a tagged image in gcr.io for echo-app:v2
- The
echo-web.tar.gzfile has already been copied to a Google Cloud Storage bucket calledgs://[PROJECT_ID]during the lab provision. Navigate to Storage, confirm the file exists in the bucket. Then, click the file name and copy the URL of the file from its detail page. - Go to Cloud shell and write commands.
gsutil cp gs://sureskills-ql/challenge-labs/ch04-kubernetes-app-deployment/echo-web.tar.gz . tar -xvf echo-web.tar.gz
- In the GCP Console go to Cloud Shell copy and paste the command.
- It will tag image in gcr.io for echo-app:v2
gcloud builds submit --tag gcr.io/$DEVSHELL_PROJECT_ID/echo-app:v2 .
- In the GCP Console go to Cloud Shell copy and paste the command.
- Configuration as follow:
Cluster Name: echo-cluster
Zone: us-central1-a
gcloud container clusters get-credentials echo-cluster --zone us-central1-a 
2. Echo-app:v2 is running on the Kubernetes cluster
- In the GCP Console go to Cloud Shell copy and paste the command.
- It will create an application image with a v1 tag that has been pushed to the gcr.io repository
kubectl create deployment echo-web --image=gcr.io/qwiklabs-resources/echo-app:v1 kubectl expose deployment echo-web --type=LoadBalancer --port 80 --target-port 8000
3.The Kubernetes cluster deployment reports 2 replicas.
- In the GCP Console go to Cloud Shell copy and paste the command.
kubectl scale deploy echo-web --replicas=2
4.The application must respond to web requests with V2.0.0
- In the GCP Console go to Cloud Shell copy and paste the command.
kubectl edit deploy echo-web- Change the image version ‘v1’ to ‘v2’ by pressing “i”.
- Save by esc -> Esc → “:wq”.
Congratulations! Done with the challenge lab.
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