version: '3.8'

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      # Database Connection Configuration
      # We removed the ':-default' syntax. 
      # Now, the container will strictly use what is provided by the host environment.
      - DB_TYPE=${DB_TYPE}
      - DB_HOST=${DB_HOST}
      - DB_PORT=${DB_PORT}
      - DB_USER=${DB_USER}
      - DB_PASSWORD=${DB_PASSWORD}
      - DB_NAME=${DB_NAME}
      
      # Application Keys
      - API_KEY=${API_KEY}