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Intermediate 18 min readModule: Module 5: Docker Compose Multi-Container Stacks

Docker Compose: Multi-Service Local Stacks

Spin up full-stack local development environments (App + PostgreSQL + Redis) with a single command.

What You Will Learn in This Lesson

  • Defining multi-container services in docker-compose.yml
  • Automatic bridge networking and service name DNS resolution
  • Persisting database data using named volumes

Introduction & Core Concept

Docker Compose is a tool for defining and running multi-container Docker applications using a YAML configuration file.
WHY DOES THIS MATTER IN THE REAL WORLD?

Instead of manually configuring and installing PostgreSQL, Redis, and Node, new developers run 'docker compose up' and have a full local stack ready in seconds.

Multi-Service docker-compose.yml

yaml
yaml
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services:
  web:
    build: .
    ports: ["3000:3000"]
    environment:
      - DATABASE_URL=postgres://user:pass@db:5432/app
    depends_on:
      - db
  db:
    image: postgres:16-alpine
    environment:
      - POSTGRES_PASSWORD=pass
    volumes:
      - pgdata:/var/lib/postgresql/data
volumes:
  pgdata:

Line-by-Line Technical Breakdown

1depends_on ensures the database container starts before the web application.

Try It Yourself (Interactive Editor)

Modify the code in real-time and click Run to test live browser output and console logs.

Intelligent Code Runner & Live Sandbox[YAML]
YAML SOURCE EDITOR
Interactive Live Code

Industry Best Practices & Professional Standards

  • Always use named volumes for database containers to prevent data loss on container restarts.

Lesson Summary & Core Takeaways

  • Docker Compose delivers instant, reproducible multi-container development environments.