DOCKER COMPOSE - DOCUMENTATION

1. What is Docker Compose?

Docker Compose is a tool to define and manage multi-container Docker applications using a single YAML file (docker-compose.yml).

Benefits:

Start multiple services with one command.
Define volumes, networks, and dependencies.
Ideal for development and testing environments.

2. Docker Compose Structure

version: "3.9"

services:
  web:
    build: .
    ports:
      - "3000:3000"
    volumes:
      - .:/app
    depends_on:
      - db

  db:
    image: postgres:15
    environment:
      POSTGRES_USER: admin
      POSTGRES_PASSWORD: secret
      POSTGRES_DB: mydb
    volumes:
      - db_data:/var/lib/postgresql/data

volumes:
  db_data:

Commands:

Command	Description
`docker-compose up`	Build and start containers
`docker-compose up -d`	Run in background
`docker-compose down`	Stop and remove containers, networks
`docker-compose build`	Build or rebuild services
`docker-compose ps`	List services
`docker-compose logs -f`	View logs continuously
`docker-compose exec <service> bash`	Open shell inside a service container

3. Best Practices

Use .dockerignore to exclude unnecessary files from images.
Tag images with meaningful versions (myapp:1.0.0).
Use environment variables for configuration.
Separate development and production compose files.
Keep services small and focused (one process per container).

1. What is Docker Compose?

Benefits:

2. Docker Compose Structure

Commands:

3. Best Practices

4. Cheat Sheet: Docker & Docker Compose