icanhazrust - Rust Implementation

A simple web service that returns your IP address, inspired by icanhazip.com.

Features

• Returns the client's IP address
• Supports proxy headers (X-Forwarded-For, X-Real-IP, CF-Connecting-IP, etc.)
• Optional JSON output via ?format=json parameter
• Optional HTTP headers display via ?headers=true parameter
• Can combine both parameters

Building

cargo build --release

Running

cargo run --release

The server will start on http://0.0.0.0:3000

Usage Examples

Plain text IP (default)

curl http://localhost:3000/
# Output: 127.0.0.1

JSON format

curl http://localhost:3000/?format=json
# Output:
# {
#   "ip": "127.0.0.1"
# }

Show HTTP headers

curl http://localhost:3000/?headers=true
# Output:
# 127.0.0.1
#
# Headers:
# host: localhost:3000
# user-agent: curl/7.88.1
# accept: */*

JSON with headers

curl http://localhost:3000/?format=json&headers=true
# Output:
# {
#   "ip": "127.0.0.1",
#   "headers": [
#     ["host", "localhost:3000"],
#     ["user-agent", "curl/7.88.1"],
#     ["accept", "*/*"]
#   ]
# }

Configuration

To change the listening port, modify the addr variable in main.rs:

let addr = SocketAddr::from(([0, 0, 0, 0], 8080)); // Change 3000 to your desired port

Proxy Support

The service automatically detects the real client IP when behind a reverse proxy by checking these headers in order:

1. X-Real-IP
2. X-Forwarded-For (takes the first IP)
3. CF-Connecting-IP (Cloudflare)
4. True-Client-IP (Cloudflare Enterprise)
5. X-Client-IP

If none are present, it falls back to the direct connection IP.

Dependencies

• axum - Web framework
• tokio - Async runtime
• serde / serde_json - JSON serialization
• tower / tower-http - Middleware and tracing
• tracing - Logging

License

MIT