BlueGreenDeployment

This Repository would contain all the code related to Blud Green Deployment strategy on GKE

A detailed overview of the deployment strategies is presented by google here.

Getting started

Export environment variables:

gcloud config set project PROJECT_ID

Replace PROJECT_ID with the ID of the project where you want to create the cluster.

export PROJECT=$(gcloud config get-value project)

Create a GKE cluster with Anthos enabled:

gcloud container clusters create "test-cluster" \
   --zone "us-central1-a" \
   --scopes "https://www.googleapis.com/auth/cloud-platform" \
   --addons HorizontalPodAutoscaling,HttpLoadBalancing \

Get running cluster credentials:

gcloud container clusters get-credentials "test-cluster"  \
   --zone "us-central1-a" \
   --project $PROJECT

Clone repository:

git clone https://github.com/jstjyoti/BlueGreenDeployment
cd BlueGreenDeployment

Blue/Green

Create deployment with the current version of the application:

kubectl apply -f bluegreen/deployment-old.yaml

Expose the deployment using Kubernetes service:

kubectl apply -f bluegreen/service-old.yaml

Check if deployment and service created successfully:

kubectl rollout status deploy app-01 -w
kubectl get svc/app -w

Wait for external IP to be allocated before proceeding. Press CTRL-C to end the watch loop.

On a new terminal, get the service IP and send requests to the current deployment:

while(true); \
do \
curl "http://$(kubectl get svc app -o jsonpath="{.status.loadBalancer.ingress[0].ip}"):8080/version"; echo; \
done

Create deployment with the new version of the application:

kubectl apply -f bluegreen/deployment-old.yaml

Check if the new deployment created successfully:

kubectl rollout status deploy app-02 -w

Update the service to point to the new version:

kubectl apply -f bluegreen/service-new.yaml

Monitor the response changing on the terminal where curl command was executed.

Cleanup:

kubectl delete -f bluegreen/ --ignore-not-found