https://roadmap.sh/projects/multi-container-service

MULTI-CONTAINER PROJECT

A minimal, unauthenticated REST API for managing a todo list, built with Node.js, Express, Mongoose and MongoDB.

This project demonstrates:

• Basic CRUD API
• MongoDB persistence
• Containerization with Docker & docker-compose
• Infrastructure as Code (Terraform + Ansible)
• CI/CD deployment (GitHub Actions)
• (Bonus) Nginx reverse proxy setup

Features / Endpoints

Method	Endpoint	Description	Request Body (JSON)
GET	/todos	List all todos	—
POST	/todos	Create a new todo	{ "title": "Buy milk", "completed": false }
GET	/todos/:id	Get one todo by ID	—
PUT	/todos/:id	Update todo (full or partial)	{ "title": "...", "completed": true }
DELETE	/todos/:id	Delete a todo	—

Note: No authentication / authorization is implemented.

Tech Stack

• Runtime Node.js
• Framework Express
• Database MongoDB
• ODM Mongoose
• Dev tooling nodemon
• Container Docker + docker-compose
• IaC Terraform (server), Ansible (configuration)
• CI/CD GitHub Actions
• Bonus Nginx (reverse proxy)

Project Structure (typical layout)

todo-api/
├── src/
│   ├── controllers/
│   │   └── todo.controller.js
│   ├── config/
│   │   └── db.js
│   ├── routes/
│   │   └── todos.routes.js
│   ├── app.js              # or index.js
│   └── index.js
├── .dockerignore
├── .gitignore
├── Dockerfile
├── docker-compose.yml
├── terraform/
│   ├── main.tf
│   ├── variables.tf
│   └── ...
├── ansible/
│   ├── playbook.yml
│   └── roles/
├── .github/
│   └── workflows/
│       └── deploy.yml
└── README.md

Quick Start (Local Development)

# 1. Start MongoDB + API
docker compose up -d

# 2. With hot-reload (recommended for development)
docker compose -f docker-compose.yml -f docker-compose.dev.yml up

API will be available at: http://localhost:3000

Local Requirements

• Docker 20.10+
• Docker Compose v2
• (optional) Node.js 18+ & npm/yarn/pnpm — for local non-docker development

Docker Compose Services

Service	Port mapping	Purpose	Persisted?
api	3000 → 3000	Node.js / Express application	—
mongo	—	MongoDB database	Yes
mongo-express	8081 → 8081 (opt.)	Web UI for browsing MongoDB	—
nginx	80 → 80 (bonus)	Reverse proxy (bonus)	—

Deployment Architecture

+-------------------+       +---------------------+       +-----------------+
|  GitHub           |       |  Remote VM          |       |  Docker Host    |
|  (main branch)    | →     |  (DigitalOcean /    | →     |  • api          |
|  → GitHub Actions |       |   AWS / ...)        |       |  • mongo        |
+-------------------+       |  • Docker + Compose |       |  • nginx (bonus)|
                            +---------------------+       +-----------------+
                                       ↑
                               Terraform (create VM)
                                       ↑
                                 Ansible (setup)

Deployment Steps (One-time setup)

1. Create infrastructure

   cd terraform
   terraform init
   terraform apply

2. Configure server & deploy first version

   cd ansible
   ansible-playbook -i inventory.yml playbook.yml

3. Future changes → just push to main → GitHub Actions handles build & deploy

CI/CD (GitHub Actions)

Typical workflow triggers on:

• push to main
• pull request to main

Steps usually include:

• lint & test (if you added tests)
• build & push Docker image to Docker Hub / GHCR
• SSH into server
• docker compose pull && docker compose up -d

Secrets needed in Multi-Container-Application settings:

• SSH_PRIVATE_KEY
• SERVER_IP or HOST
• DOCKERHUB_USERNAME / DOCKERHUB_TOKEN (if using Docker Hub)

Bonus – Domain + HTTPS (manual / optional steps)

1. Point domain A record → server public IP
2. Install certbot inside nginx container or on host
3. Obtain Let's Encrypt certificate
4. Update nginx config to use SSL

Or use a managed solution (Cloudflare, Traefik, Caddy, etc.)

Todo (Project Improvement Ideas)

• Add input validation (Joi / Zod / express-validator)
• Add basic tests (Jest + supertest)
• Implement health-check endpoint /health
• Add API documentation (Swagger / Redoc)
• Add rate limiting
• Add simple authentication (JWT / API key)
• Use MongoDB transactions (if needed)
• Add logging (winston / pino)
• Add environment-based configuration (dotenv / convict)

License

MIT