Docker Compose for Beginners: Your First Stack in 15 Minutes

What is Docker Compose?

Docker Compose is the secret weapon of every homelab enthusiast. It allows you to define and run multi-container applications with a single YAML file. Instead of running multiple complex docker commands, you describe your entire stack in one file and launch it with one command.

Think of Docker Compose as a recipe book for your applications. You write down all the ingredients (containers), how they connect (networks), and where they store data (volumes) - then Compose handles the rest.

Prerequisites

Before we start, make sure you have Docker and Docker Compose installed. On most modern systems, Docker Compose comes bundled with Docker Desktop or can be installed as a plugin.

# Check if Docker is installed
docker --version

# Check if Docker Compose is installed
docker compose version

If you see version numbers for both commands, you're ready to go. If not, visit the official Docker documentation to install Docker for your operating system.

Understanding the docker-compose.yml File

Every Docker Compose project starts with a docker-compose.yml file. This file uses YAML syntax to define your services, networks, and volumes.

version: "3.8"

services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./html:/usr/share/nginx/html
    restart: unless-stopped

  database:
    image: mysql:8.0
    environment:
      MYSQL_ROOT_PASSWORD: secret
      MYSQL_DATABASE: myapp
    volumes:
      - db_data:/var/lib/mysql
    restart: unless-stopped

volumes:
  db_data:

Key Components:

• version: The Compose file format version
• services: The containers that make up your application
• volumes: Persistent storage that survives container restarts
• networks: How containers communicate (auto-created by default)

Your First Stack: WordPress in 5 Minutes

Let's deploy a complete WordPress site with a MySQL database. Create a new directory and add this docker-compose.yml file:

version: "3.8"

services:
  wordpress:
    image: wordpress:latest
    ports:
      - "8080:80"
    environment:
      WORDPRESS_DB_HOST: db
      WORDPRESS_DB_USER: wordpress
      WORDPRESS_DB_PASSWORD: wordpress
      WORDPRESS_DB_NAME: wordpress
    volumes:
      - wordpress_data:/var/www/html
    depends_on:
      - db
    restart: unless-stopped

  db:
    image: mysql:8.0
    environment:
      MYSQL_DATABASE: wordpress
      MYSQL_USER: wordpress
      MYSQL_PASSWORD: wordpress
      MYSQL_ROOT_PASSWORD: rootpassword
    volumes:
      - db_data:/var/lib/mysql
    restart: unless-stopped

volumes:
  wordpress_data:
  db_data:

Essential Docker Compose Commands

Navigate to the directory containing your docker-compose.yml and use these commands:

# Start all services in the background
docker compose up -d

# View running containers
docker compose ps

# View logs from all services
docker compose logs -f

# Stop all services
docker compose down

# Stop and remove all data (careful!)
docker compose down -v

After running docker compose up -d, visit http://localhost:8080 to see your WordPress site!

Best Practices for Homelab

• Always use restart policies: Add restart: unless-stopped to ensure services start after reboots
• Use named volumes: Named volumes are easier to manage and backup than bind mounts
• Set resource limits: Prevent runaway containers from consuming all system resources
• Use .env files: Store sensitive data like passwords in .env files, not in the compose file
• Version your compose files: Keep them in Git for easy rollback and documentation

Next Steps

Congratulations! You've just deployed your first Docker Compose stack. From here, the possibilities are endless. You can deploy media servers, password managers, file storage, and dozens of other self-hosted services using the same principles.

The key to mastering Docker Compose is practice. Start with simple stacks and gradually add more complexity as you become comfortable with the concepts.