📄 Sample YAML File for Docker-Compose

version: '3.8'
 
services:
  🌐 web:
    image: nginx:alpine
    ports:
      - "80:80"
    volumes:
      - ./web-content:/usr/share/nginx/html
    networks:
      - frontend
    depends_on:
      - api
 
  🔧 api:
    image: node:14
    working_dir: /app
    environment:
      NODE_ENV: production
    volumes:
      - ./api:/app
    networks:
      - frontend
      - backend
    ports:
      - "3000:3000"
 
  🗄️ db:
    image: postgres:13
    environment:
      POSTGRES_DB: mydb
      POSTGRES_USER: myuser
      POSTGRES_PASSWORD: mypassword
    volumes:
      - postgres-data:/var/lib/postgresql/data
    networks:
      - backend
 
  📊 monitoring:
    image: prom/prometheus
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus-config:/etc/prometheus
    networks:
      - backend
 
networks:
  🌉 frontend:
    driver: bridge
  🌉 backend:
    driver: bridge
 
volumes:
  📦 postgres-data:
  📦 prometheus-config:

📝 Explanation

Services

• 🌐 web:

  • Image: Uses the lightweight nginx:alpine image.
  • Ports: Maps port 80 on the host to port 80 on the container.
  • Volumes: Mounts the ./web-content directory on the host to /usr/share/nginx/html in the container.
  • Networks: Connected to the frontend network.
  • Depends_on: Depends on the api service.

• 🔧 api:

  • Image: Uses the node:14 image.
  • Working Directory: Sets /app as the working directory.
  • Environment: Sets NODE_ENV to production.
  • Volumes: Mounts the ./api directory on the host to /app in the container.
  • Networks: Connected to both frontend and backend networks.
  • Ports: Maps port 3000 on the host to port 3000 on the container.

• 🗄️ db:

  • Image: Uses the postgres:13 image.
  • Environment: Sets up the database with POSTGRES_DB, POSTGRES_USER, and POSTGRES_PASSWORD.
  • Volumes: Mounts a named volume postgres-data to /var/lib/postgresql/data.
  • Networks: Connected to the backend network.

• 📊 monitoring:

  • Image: Uses the prom/prometheus image.
  • Ports: Maps port 9090 on the host to port 9090 on the container.
  • Volumes: Mounts the ./prometheus-config directory on the host to /etc/prometheus in the container.
  • Networks: Connected to the backend network.

Networks

• 🌉 frontend: A bridge network for the web and api services.
• 🌉 backend: A bridge network for the api, db, and monitoring services.

Volumes

• 📦 postgres-data: A named volume for persisting PostgreSQL data.
• 📦 prometheus-config: A named volume for storing Prometheus configuration files.