Express.js Application with Monitoring

A simple Express.js REST API application with built-in monitoring capabilities, containerized with Docker for easy local development.

📋 Table of Contents

• Features
• Prerequisites
• Installation
• Running the Application
  • Local Development
  • Docker Development
• API Endpoints
• Available Scripts
• Project Structure
• Docker Configuration
• Monitoring
• Troubleshooting
• Contributing
• License

✨ Features

• Express.js REST API server
• Built-in health and metrics endpoints
• Docker containerization with development/production profiles
• Hot reload development with nodemon
• Lightweight and fast startup
• Ready for monitoring integration

🛠️ Prerequisites

• Node.js 18+
• Docker and Docker Compose
• npm or yarn

📦 Installation

1. Clone the repository

   git clone <repository-url>
   cd monitoring-get-started

2. Install dependencies

   npm install

🚀 Running the Application

Local Development

# Start the application locally
npm start

# Start with hot reload
npm run dev

The application will be available at http://localhost:3000

Docker Development

Development Mode (with hot reload)

npm run docker:up-dev

Production Mode

npm run docker:up

🌐 API Endpoints

• GET / - Root endpoint with API information
• GET /api/test - Test endpoint returning JSON response
• GET /health - Health check endpoint
• GET /metrics - Prometheus metrics endpoint

📜 Available Scripts

# Application Scripts
npm start                    # Start the application
npm run dev                 # Start with nodemon (hot reload)

# Docker Scripts  
npm run docker:build        # Build Docker images
npm run docker:up           # Start production containers
npm run docker:up-dev       # Start development container
npm run docker:down         # Stop all containers
npm run docker:logs         # View container logs

# Monitoring Scripts
npm run monitoring:up       # Start monitoring stack
npm run monitoring:full     # Start app + monitoring
npm run monitoring:down     # Stop monitoring services

📁 Project Structure

monitoring-get-started/
├── index.js                    # Main Express.js application
├── package.json               # Dependencies and scripts
├── Dockerfile                 # Container configuration
├── docker-compose.yml         # Multi-service orchestration
├── prometheus.yml             # Prometheus configuration
├── grafana/                   # Grafana provisioning
│   └── provisioning/
│       ├── datasources/       # Auto-configure Prometheus
│       └── dashboards/        # Pre-built dashboards
├── README.md                  # This file
└── MONITORING.md              # Detailed monitoring guide

� Docker Configuration

The application supports multiple deployment modes using Docker Compose profiles:

Development Profile

npm run docker:up-dev

• Hot reload with nodemon
• Source code mounted as volume
• Runs on port 3000

Production Profile

npm run docker:up

• Optimized production build
• No source code mounting
• Runs on port 3000

Monitoring Profile

npm run monitoring:up

• Prometheus, Grafana, Node Exporter
• Data persistence with Docker volumes
• See MONITORING.md for details

📊 Monitoring

This application includes built-in monitoring capabilities with Prometheus and Grafana.

For complete monitoring setup and usage instructions, see MONITORING.md

Quick monitoring commands:

npm run monitoring:full     # Start app + full monitoring stack
npm run monitoring:up       # Start monitoring services only

🐛 Troubleshooting

Application won't start

# Check if port 3000 is in use
lsof -i :3000

# View application logs
npm run docker:logs

Docker issues

# Rebuild containers
npm run docker:down
docker system prune -f
npm run docker:up

# Check container status
docker-compose ps

Permission errors (macOS/Linux)

# Fix Docker volume permissions
sudo chown -R $USER:$USER .

Port conflicts

If you encounter port conflicts, modify the ports in docker-compose.yml:

• Application: 3000:3000 → YOUR_PORT:3000
• Monitoring services: See MONITORING.md

🤝 Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📝 License

This project is licensed under the ISC License - see the package.json file for details.

Happy coding! 🚀