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Docker Tutorial — Part 6: Docker Compose

In real applications, one container is never enough. A backend talks to a database, cache, and sometimes a frontend. Managing this manually becomes painful.

What is Docker Compose?

Docker Compose allows you to define and run multiple containers using one file.

The docker-compose.yml File

This file describes:

• Services (containers)
• Images
• Ports
• Volumes
• Networks

Basic Example (Web + Database)

version: "3.9"

services:
  web:
    image: nginx
    ports:
      - "8080:80"

  db:
    image: mysql
    environment:
      MYSQL_ROOT_PASSWORD: root

Start the Application

docker compose up -d

Stop Everything

docker compose down

Why Docker Compose Matters

• One command starts everything
• Perfect for local development
• Industry standard workflow

Real-World Thinking

Every modern backend you deploy will eventually use Compose or Kubernetes.

Next, we learn how Docker images are actually built.