feat: integrate TypeORM with PostgreSQL and AWS Secrets Manager for d…

[DamirSt]

Task 8 PR Description

What was done?

• Implemented Task 8 end-to-end for Cart Service on AWS.
• Added infrastructure as code with CDK and moved it into this repository under cdk-infra.
• Deployed NestJS Cart API to AWS Lambda with API Gateway proxy integration.
• Added PostgreSQL RDS instance in a VPC with security groups allowing Lambda to connect on port 5432.
• Added TypeORM integration and PostgreSQL entities:
  • carts: id (PK, generated), user_id (not null), status enum (OPEN, ORDERED), created_at, updated_at
  • cart_items: id (PK, generated), cart_id (FK -> carts.id), product_id, count, product_snapshot
• Added DB connection configuration using ConfigService and environment variables.
• Added secure credential loading from AWS Secrets Manager via DB_SECRET_ARN.
• Passed DB connection environment variables from CDK to Lambda.
• Fixed backend API Gateway CORS configuration so browser preflight and cross-origin requests work from CloudFront.
• Fixed backend Lambda to connect to RDS PostgreSQL with SSL (resolved 502 runtime failures caused by DB connection rejection).
• Updated cart API responses to include created_at and updated_at fields.
• Integrated frontend cart interactions with Cart Service API.
• Updated frontend cart flow to use backend endpoints for:
  • loading cart
  • updating cart item count
  • clearing cart
• Extended frontend auth interceptor so cart requests include Authorization header.
• Updated frontend environment configuration to point cart endpoint to deployed API.
• Redeployed backend stack and frontend stack.

Additional scope

• FE integration verified in AWS_FOR_JS/FE:
  • cart load from API
  • add product to cart
  • remove cart item / clear cart
  • cart total calculation in checkout/cart views
• Added CORS configuration and API Gateway 4XX/5XX gateway responses with CORS headers.
• Repo consolidation: cdk-infra is now inside nodejs-aws-cart-api.
• Backend infrastructure changes:
  • API Gateway CORS preflight/default response behavior
  • Lambda environment configuration (DB_SSL=true)
• Frontend deployment updates:
  • fresh build
  • S3/CloudFront deployment via CDK

Verification

• Preflight request to cart endpoint returns 204 with CORS headers.
• Authenticated GET to cart endpoint returns 200.
• Cart PUT and GET responses include created_at and updated_at.
• Frontend deployed and available via CloudFront.

Link to Cart Service API

• https://6o18jg2125.execute-api.us-east-1.amazonaws.com/prod/api/profile/cart

Frontend URL

• https://duivy9lb5sq2a.cloudfront.net