IP Extractor

Particularly for auditing reasons, it is often necessary to know the true public IP address of a client.

Presets

There a few default extractors available. Select the one that fits your environment best.

• peer-ip: The direct IP address of the peer that connected to the server
• rightmost-x-forwarded-for: The rightmost IP address in the X-Forwarded-For header
• x-real-ip: The X-Real-IP header, commonly used by Nginx
• fly-client-ip: The Fly-Client-IP header, used by Fly.io
• cf-connecting-ip: The CF-Connecting-IP header, used by Cloudflare
• true-client-ip: The True-Client-IP header

This value can be used in the ip_preset field of the config.yaml file.

ip_preset: peer-ip

Custom Extractors

In your main.rs where you initialize Rhombus, create a function which effectively takes the headers of a request, and potentially pulls out the IP address.

use http::{header::HeaderMap, Extensions};
use std::net::IpAddr;

/// Extracts the IP address from the `Custom-Client-IP` header
pub fn maybe_custom_client_ip(headers: &HeaderMap, _: &Extensions) -> Option<IpAddr> {
    headers
        .get("Custom-Client-IP")
        .and_then(|hv| hv.to_str().ok())
        .and_then(|s| s.parse::<IpAddr>().ok())
}

Then, you can use this function to configure your Builder:

let app = rhombus::Builder::default()
    // ...
    .extractor(maybe_custom_client_ip)
    // ...