Docker Compose for Flask + PostgreSQL

services:
  web:
    build: .
    command: gunicorn -b 0.0.0.0:5000 app:app
    ports:
      - target: 5000
        mode: ingress
    environment:
      - DATABASE_URL=postgresql://postgres:${POSTGRES_PASSWORD}@db:5432/flask
      - FLASK_SECRET_KEY=${FLASK_SECRET_KEY}
    healthcheck:
      test:
        - CMD
        - curl
        - -f
        - http://localhost:5000/
      interval: 30s
      timeout: 5s
      retries: 3
    depends_on:
      - db
    deploy:
      resources:
        reservations:
          cpus: "0.5"
          memory: 256M
    restart: unless-stopped
  db:
    image: postgres:16
    ports:
      - target: 5432
        mode: host
    environment:
      - POSTGRES_DB=flask
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
    healthcheck:
      test:
        - CMD-SHELL
        - pg_isready -U postgres
      interval: 10s
      timeout: 5s
      retries: 5
    deploy:
      resources:
        reservations:
          cpus: "0.5"
          memory: 256M
    restart: unless-stopped
    x-defang-postgres: true