Crate axum_tariff 

axum-tariff

“Some countries… they need to wait.” — You, probably

🚦 Middleware for Axum that introduces configurable request delays based on the client’s country (IP geolocation).

Inspired by the chaotic beauty of international trade wars, this crate uses the MaxMind GeoIP2 database to detect IPs by country and apply a delay (“tariff”) per your configuration.

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✨ Features

• ⏱️ Delay requests from specific countries
• 🌍 Uses MaxMind DB for IP-to-country mapping
• 🧱 Simple tower::Layer and tower::Service integration
• 🧪 Tested with mock MaxMind DB and real IPs

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🚀 Usage

1. Add to your project

cargo add axum-tariff

2. Add the middleware

use axum::{routing::get, Router};
use std::{net::IpAddr, time::Duration};
use axum_tariff::{Config, Reader};

#[tokio::main]
async fn main() {
    let reader = Reader::open_readfile("assets/GeoLite2-Country-Test.mmdb").unwrap();

    let layer = Config::new(reader)
        .with("US", Duration::from_secs(1))
        .with("FR", Duration::from_millis(500))
        .into_layer();

    let app: Router<()> = Router::new()
        .route("/", get(|| async { "Hello, world!" }))
        .layer(layer);


    let listener = tokio::net::TcpListener::bind("127.0.1.1:3000").await.unwrap();
    axum::serve(listener, app).await.unwrap();
}

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🧪 Running the Tests

This crate includes tests that use the GeoLite2-Country-Test.mmdb. You’ll need to place it at:

assets/GeoLite2-Country-Test.mmdb

Then:

cargo test

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📦 Example: Applying a 2s delay to China

let config = Config::new(reader)
    .with("CN", Duration::from_secs(2));

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📄 License

MIT

Structs

Config

Configuration for applying request delays (tariffs) based on IP country.

Reader

A reader for the MaxMind DB format. The lifetime 'data is tied to the lifetime of the underlying buffer holding the contents of the database file.

TariffLayer

A tower::Layer that wraps services to apply country-based request delays.

TariffService

A tower::Service that introduces delay based on the client IP address’s country.