Create Service & Task

In the final step of the backend deployment, we define the runtime configuration for the Spring Boot application and launch it as a stable ECS Service.

1. Create Task Definition

  1. Navigate to Amazon ECS > Task definitions > Create new task definition.
  2. Task definition configuration:
    • Family: bandup-backend.
    • Launch type: AWS Fargate.
    • OS/Architecture: Linux/X86_64.
    • Task size: 1 vCPU and 2 GB Memory.
      • Note: Java applications (Spring Boot) generally require more memory than Node.js apps to handle the JVM heap effectively.
    • Task Role & Execution Role: Select ecsTaskExecutionRole.

Task Definition Overview

  1. Container Details:

    • Name: bandup-be-container.
    • Image URI: Enter the ECR URI (.../band-up-backend:v1.0.0).
    • Container Port: 8080 (Default Spring Boot port).

  2. Environment Configuration (Best Practice): Instead of manually entering sensitive variables (Database URL, User, Password) in plain text, we load them from a secure file stored in S3.

    • Environment files: Add the S3 ARN of your .env file (e.g., arn:aws:s3:::bandup2025-fcj/.env).
    • Requirement: Ensure your ecsTaskExecutionRole has permission to read this S3 object.

Container and S3 Env Config

2. Create ECS Service

Deploy the task definition to the cluster.

  1. Navigate to bandup-cluster > Services > Create.
  2. Deployment configuration:
    • Compute options: FARGATE.
    • Family: bandup-backend (Revision 7 or latest).
    • Service name: bandup-backend-service.
    • Desired tasks: 1.

Service Deployment Config

  1. Networking:
    • VPC: band-up-vpc.
    • Subnets: Select Private Subnets (private-subnet-1, private-subnet-2).
    • Security group: Select ecs-backend-sg (Created in step 5.5.2).

Service Networking

  1. Load Balancing:
    • Load balancer: Select bandup-public-alb.
    • Listener: Use existing listener 80:HTTP.
    • Target group: Create a new target group target-bandup-be.
    • Container info: Ensure traffic is routed to port 8080.

Service Load Balancing

  1. Click Create. The service will provision the Fargate tasks, pull the image, load the environment variables from S3, and register with the ALB.