Server time: ${new Date().toISOString()}
+Host: ${process.env.HOSTNAME || 'unknown'}
+ + + `); +}); + +app.get('/health', (req, res) => { + res.json({ status: 'healthy', timestamp: new Date().toISOString() }); +}); + +app.listen(PORT, () => { + console.log(`Server running on port ${PORT}`); +}); +``` + +## Step 3: Create Dockerfile + +**Dockerfile:** +```dockerfile +# Use the official Node.js runtime as base image +FROM node:18-alpine + +# Set working directory in container +WORKDIR /app + +# Copy package files +COPY package*.json ./ + +# Install dependencies +RUN npm install --production + +# Copy application code +COPY . . + +# Expose port +EXPOSE 8080 + +# Start the application +CMD ["npm", "start"] +``` + +**.dockerignore:** +``` +node_modules +npm-debug.log +.git +.gitignore +README.md +Dockerfile +.dockerignore +``` + +## Step 4: Build and Test Docker Image Locally + +```bash +# Build the Docker image +docker build -t my-node-app . + +# Test locally +docker run -p 8080:8080 my-node-app + +# Visit http://localhost:8080 to verify it works +``` + +## Step 5: Push to Google Container Registry (GCR) + +```bash +# Configure Docker to use gcloud as credential helper +gcloud auth configure-docker + +# Tag the image for GCR +docker tag my-node-app gcr.io/YOUR_PROJECT_ID/my-node-app:v1.0 + +# Push to GCR +docker push gcr.io/YOUR_PROJECT_ID/my-node-app:v1.0 +``` + +## Step 6: Create a GKE Cluster + +```bash +# Create a cluster +gcloud container clusters create my-gke-cluster \ + --num-nodes=2 \ + --zone=us-central1-a \ + --machine-type=e2-small + +# Get cluster credentials +gcloud container clusters get-credentials my-gke-cluster \ + --zone=us-central1-a +``` + +## Step 7: Create Kubernetes Deployment Files + +**deployment.yaml:** +```yaml +apiVersion: apps/v1 +kind: Deployment +metadata: + name: my-node-app + labels: + app: my-node-app +spec: + replicas: 3 + selector: + matchLabels: + app: my-node-app + template: + metadata: + labels: + app: my-node-app + spec: + containers: + - name: my-node-app + image: gcr.io/YOUR_PROJECT_ID/my-node-app:v1.0 + ports: + - containerPort: 8080 + env: + - name: NODE_ENV + value: "production" + resources: + requests: + memory: "128Mi" + cpu: "100m" + limits: + memory: "256Mi" + cpu: "200m" + livenessProbe: + httpGet: + path: /health + port: 8080 + initialDelaySeconds: 5 + periodSeconds: 10 + readinessProbe: + httpGet: + path: /health + port: 8080 + initialDelaySeconds: 5 + periodSeconds: 10 +``` + +**service.yaml:** +```yaml +apiVersion: v1 +kind: Service +metadata: + name: my-node-app-service + labels: + app: my-node-app +spec: + type: LoadBalancer + selector: + app: my-node-app + ports: + - port: 80 + targetPort: 8080 + protocol: TCP +``` + +## Step 8: Deploy to GKE + +```bash +# Apply the deployment +kubectl apply -f deployment.yaml + +# Apply the service +kubectl apply -f service.yaml + +# Check deployment status +kubectl get deployments + +# Check pods +kubectl get pods + +# Check service (get external IP) +kubectl get services +``` + +## Step 9: Verify Deployment + +```bash +# Get the external IP +kubectl get service my-node-app-service + +# Test the application (replace EXTERNAL_IP with actual IP) +curl http://EXTERNAL_IP + +# View pod logs +kubectl logs -l app=my-node-app --tail=50 +``` + +## Step 10: Scaling and Updates + +```bash +# Scale the deployment +kubectl scale deployment my-node-app --replicas=5 + +# Update the application (after building new image) +docker build -t gcr.io/YOUR_PROJECT_ID/my-node-app:v2.0 . +docker push gcr.io/YOUR_PROJECT_ID/my-node-app:v2.0 +kubectl set image deployment/my-node-app my-node-app=gcr.io/YOUR_PROJECT_ID/my-node-app:v2.0 + +# Rollback if needed +kubectl rollout undo deployment/my-node-app +``` + +## Step 11: Clean Up + +```bash +# Delete the deployment and service +kubectl delete -f deployment.yaml +kubectl delete -f service.yaml + +# Delete the cluster +gcloud container clusters delete my-gke-cluster --zone=us-central1-a + +# Delete the container image +gcloud container images delete gcr.io/YOUR_PROJECT_ID/my-node-app:v1.0 --force-delete-tags +``` + +## Automation Script + +Create a **deploy.sh** script for automation: + +```bash +#!/bin/bash +PROJECT_ID="YOUR_PROJECT_ID" +IMAGE_NAME="my-node-app" +VERSION="v1.0" +CLUSTER_NAME="my-gke-cluster" +ZONE="us-central1-a" + +echo "Building Docker image..." +docker build -t $IMAGE_NAME . + +echo "Tagging image for GCR..." +docker tag $IMAGE_NAME gcr.io/$PROJECT_ID/$IMAGE_NAME:$VERSION + +echo "Pushing to GCR..." +docker push gcr.io/$PROJECT_ID/$IMAGE_NAME:$VERSION + +echo "Deploying to GKE..." +gcloud container clusters get-credentials $CLUSTER_NAME --zone $ZONE +kubectl apply -f deployment.yaml +kubectl apply -f service.yaml + +echo "Deployment complete!" +kubectl get services +``` + +Make it executable: +```bash +chmod +x deploy.sh +``` + +This complete workflow shows you how to containerize an application, push it to Google Container Registry, and deploy it to a GKE cluster with proper configuration for production use.