CapRover IP Address Returner

A simple Node.js application that returns the visitor's IP address. This app is designed to work with CapRover and handles various deployment scenarios including CloudFlare integration.

Features

• Returns visitor's IP address
• Supports both IPv4 and IPv6
• Handles various proxy scenarios:
  • Direct connections
  • Behind CapRover proxy
  • Behind CloudFlare
  • Behind Nginx
  • Behind Azure
  • Multiple proxy layers
• Intelligent IP detection using headers:
  • CF-Connecting-IP (CloudFlare)
  • X-Forwarded-For (Standard proxy)
  • X-Real-IP (Nginx)
  • X-Client-IP (Azure)
  • Direct socket connection

Installation

# Clone the repository
git clone https://github.com/EnkodoNL/caprover-return-ip.git

# Install dependencies
npm install

# Start the server
npm start

Deployment to CapRover

1. Create a new app in your CapRover dashboard

2. Deploy using one of these methods:

   Method 1: CLI Deployment

   Make sure you have the CapRover CLI installed:

   npm install -g caprover

   caprover deploy

   Method 2: Manual Deployment

   • Download the caprover-deploy.tar tarball from the Releases page
   • Upload the tarball in the CapRover dashboard under "Method 2: Tarball"

   Method 3: GitHub Integration

   • Push your code to GitHub
   • Set up automatic deployment in CapRover dashboard using your repository URL

How It Works

The application uses a hierarchical approach to determine the correct IP address:

1. First checks for CloudFlare's CF-Connecting-IP header
2. Falls back to X-Forwarded-For header
3. Then checks X-Real-IP (Nginx)
4. Then checks X-Client-IP (Azure)
5. Finally uses the socket's remote address if no proxy headers are present

The app includes special handling for:

• IPv6 addresses with port information
• Multiple IP addresses in forwarded headers (takes the first one)
• Different IP address formats
• Port information removal

Environment Variables

• PORT: Server port (default: 3000)
• FORMAT: Response format
  • If not set: returns plain IP address
  • If set to "json": returns JSON with IP and version
• EMPTY_RESPONSE: Custom response when IP cannot be determined (default: "x.x.x.x")

Example Response

Default Format

192.168.1.1

or

2001:db8::1

JSON Format (FORMAT=json)

{
  "ip": "192.168.1.1",
  "version": "ipv4"
}

or

{
  "ip": "2001:db8::1",
  "version": "ipv6"
}

Technical Details

• Built with Node.js and Express
• Minimal dependencies for better security and performance
• Uses CapRover's Node.js 20 template
• Includes IP cleaning functionality:
  • Removes port information
  • Handles IPv6 addresses in brackets
  • Extracts first IP from forwarded headers
  • Automatic IP version detection (ipv4/ipv6)

License

MIT