Container Registry & Compute

This section covers Steps 13–15: building and pushing Docker images to ECR, deploying the OCR service on ECS Fargate, and deploying the Backend on Elastic Beanstalk.

Step 13: Create ECR & Push Docker Images

13.1 Create Repositories on ECR

aws ecr create-repository --repository-name smartinvoice-backend --region ap-southeast-1
aws ecr create-repository --repository-name smartinvoice-ocr --region ap-southeast-1

(Or manually via Console: ECR → Repositories → Create repository)

13.2 Authenticate Docker to AWS ECR

Replace <ACCOUNT_ID> with your 12-digit AWS Account ID:

aws ecr get-login-password --region ap-southeast-1 | \
  docker login --username AWS --password-stdin <ACCOUNT_ID>.dkr.ecr.ap-southeast-1.amazonaws.com

13.3 Build & Push Backend (.NET 9)

# Move into the API folder
cd SmartInvoice.API

# Build Docker image
docker build -t smartinvoice-backend .

# Tag to match the ECR repository
docker tag smartinvoice-backend:latest <ACCOUNT_ID>.dkr.ecr.ap-southeast-1.amazonaws.com/smartinvoice-backend:latest

# Push to AWS
docker push <ACCOUNT_ID>.dkr.ecr.ap-southeast-1.amazonaws.com/smartinvoice-backend:latest

13.4 Build & Push OCR Service (Python)

[!NOTE] The OCR image is large (~2–3 GB). Ensure a stable internet connection.

# Move into the OCR folder
cd ../invoice_ocr

# Build Docker image
docker build -t smartinvoice-ocr .

# Tag
docker tag smartinvoice-ocr:latest <ACCOUNT_ID>.dkr.ecr.ap-southeast-1.amazonaws.com/smartinvoice-ocr:latest

# Push to AWS
docker push <ACCOUNT_ID>.dkr.ecr.ap-southeast-1.amazonaws.com/smartinvoice-ocr:latest

[!TIP] If you get a “Permission Denied” error on push, verify that your IAM User has the AmazonEC2ContainerRegistryFullAccess policy.

Step 14: Deploy OCR on ECS Fargate

14.1 Create ECS Cluster

Console: ECS → Clusters → Create

14.2 Create Task Definition

Console: ECS → Task definitions → Create new task definition

14.3 Create Cloud Map Namespace

[!TIP] Cost Saving: Cloud Map allows services to discover each other via internal DNS (e.g., ocr.smartinvoice.local), saving approximately $18/month by eliminating the need for an Internal Load Balancer.

Console: AWS Cloud Map → Create namespace

14.4 Service Discovery Configuration

When creating the ECS Service in the next step, AWS will automatically register the IP addresses of your running tasks into the ocr.smartinvoice.local domain name. This allows the Backend to call the OCR service directly.

14.5 Deploy ECS Service

Console: ECS → Clusters → smartinvoice-cluster → Services → Create

A. Compute configuration

• Compute options: Capacity provider strategy
• Strategy: Use custom (Advanced) → Fargate spot (Cost saving: 50-70%) (Weight: 1, Base: 0)

B. Deployment configuration

• Application type: Service
• Task definition: Family smartinvoice-ocr-task (LATEST)
• Service name: smartinvoice-ocr-task-service
• Desired tasks: 2
• Deployment controller: Rolling update

C. Networking

• VPC: smartinvoice-vpc
• Subnets: Select both Private subnets (1a, 1b)
• Security group: smartinvoice-ocr-sg
• Public IP: ❌ Turned off (required for Private Subnet)

D. Load balancing & Service discovery

• Load balancing: Select 🔵 None (to save costs).
• Service discovery:
  • Use service discovery: ✅ (Check this).
  • Namespace: Select smartinvoice.local.
  • Service name: Enter ocr.
  • DNS record type: Select A record.
  • TTL: 15 / 60 seconds.

→ Click Create ✅. Once the Service is Running, update the /SmartInvoice/prod/OCR_API_ENDPOINT parameter in SSM to http://ocr.smartinvoice.local:5000.

Step 15: Deploy Backend on Elastic Beanstalk

15.1 Step 1: Configure Environment

15.2 Step 2: Configure Service Access

15.3 Step 3: Networking

15.4 Step 4: Instance Traffic & Scaling

15.5 Step 5: Monitoring

• Monitoring: Basic (or Enhanced for detailed metrics)

15.6 Step 6: Review & Create

Click Submit and wait 5–10 minutes for the environment to be provisioned.

15.7 Dockerrun.aws.json (for CI/CD)

After the environment is ready, this file is used by GitHub Actions to deploy code from ECR:

{
  "AWSEBDockerrunVersion": "1",
  "Image": {
    "Name": "<ACCOUNT_ID>.dkr.ecr.ap-southeast-1.amazonaws.com/smartinvoice-backend:latest",
    "Update": "true"
  },
  "Ports": [
    {
      "ContainerPort": 8080,
      "HostPort": 80
    }
  ]
}