tower-fault

tower-fault is a library for injecting various faults into a tower::Service.

Layers

You can use the following layers to inject faults into a service:

• ErrorLayer - randomly inject errors into a service.
• LatencyLayer - randomly add latency into a service.

Example usage

use tower_fault::{
    error::ErrorLayer,
    latency::LatencyLayer,
};
use tower::{service_fn, ServiceBuilder};

struct MyRequest {
    value: u64
}

async fn my_service(req: MyRequest) -> Result<(), String> {
    Ok(())
}

// LatencyLayer with a 10% probability of injecting 200 to 500 milliseconds
// of latency.
let latency_layer = LatencyLayer::new(0.1, 200..500);

// ErrorLayer that injects an error if the request value is greater than 10.
let error_layer = ErrorLayer::new(|req: &MyRequest| req.value > 10, |_: &MyRequest| String::from("error"));

let service = ServiceBuilder::new()
    .layer(latency_layer)
    .service(service_fn(my_service));