🛳️ Docker Series: Episode 8 — Docker Compose: Build Multi-Container Apps Like a Boss

🎬 "Tired of typing long docker run commands for every container? Wish you could launch your entire app stack with one file and one command? Meet Docker Compose — the superhero of multi-container development."

🧠 What is Docker Compose?

Docker Compose lets you define and run multi-container apps using a simple YAML file.

Instead of typing multiple docker run commands, you:

• Create a docker-compose.yml file
• Define services (containers)
• Run everything with: docker-compose up

🧱 Sample Project: Node.js + MongoDB

Let’s say you have:

• A backend Node.js app
• A MongoDB database

Here’s how to spin up both with Compose.

📁 Project Structure

my-app/ ├── docker-compose.yml ├── backend/ │ ├── Dockerfile │ └── index.js 

🧾 docker-compose.yml

version: '3.8' services: mongo: image: mongo container_name: mongo ports: - "27017:27017" backend: build: ./backend container_name: backend ports: - "3000:3000" depends_on: - mongo environment: - MONGO_URL=mongodb://mongo:27017 

🛠️ backend/Dockerfile

FROM node:18 WORKDIR /app COPY . . RUN npm install EXPOSE 3000 CMD ["node", "index.js"] 

🚀 Run It All

In the project root:

docker-compose up -d 

🎉 Both MongoDB and your backend are up, connected, and running.

🧰 Useful Docker Compose Commands

Start all services:

docker-compose up -d 

Stop all services:

docker-compose down 

View logs:

docker-compose logs -f 

Rebuild (if code changes):

docker-compose up --build 

🔍 Why Use Docker Compose?

• 📦 Reproducibility: Define your entire stack in one file
• ⚡ Speed: One command to build, run, stop
• 🤝 Connectivity: Services can talk via service name (e.g. mongo)

✅ Bonus Tips

• Use .env files to manage environment variables
• Use volumes: in Compose to persist data
• Use profiles: to control dev/staging/test environments

🔮 Up Next: Docker Compose + Volumes + Networks (Real Project Setup)

In Episode 9, we’ll:

• Add named volumes and custom networks to our Compose file
• Run a full-stack project with frontend, backend, and DB

💬 Let’s Build Together

Have you used Docker Compose before?
Want help creating your own docker-compose.yml?

Drop your config or questions below — I’m here to help you Docker smarter.

❤️ If this helped you simplify your Docker life, hit like, comment, or share it with your dev community.

🎬 Next: “Docker Compose: Real-World Setup with Volumes + Networks + Frontend”