reqwest-middleware/README.md

reqwest-middleware

A crate implementing a wrapper around reqwest to allow for client middleware chains.

This crate provides functionality for building and running middleware but no middleware implementations. This repository also contains a couple of useful concrete middleware crates:

• reqwest-retry: retry failed requests.
• reqwest-tracing: tracing integration, optional opentelemetry support.

Overview

The reqwest-middleware client exposes the same interface as a plain reqwest client, but ClientBuilder exposes functionality to attach middleware:

# Cargo.toml
# ...
[dependencies]
reqwest = "0.11"
reqwest-middleware = "0.1.1"
reqwest-retry = "0.1.1"
reqwest-tracing = "0.1.2"
tokio = { version = "1.12.0", features = ["macros", "rt-multi-thread"] }

use reqwest_middleware::{ClientBuilder, ClientWithMiddleware};
use reqwest_retry::{RetryTransientMiddleware, policies::ExponentialBackoff};
use reqwest_tracing::TracingMiddleware;

#[tokio::main]
async fn main() {
    // Retry up to 3 times with increasing intervals between attempts.
    let retry_policy = ExponentialBackoff::builder().build_with_max_retries(3);
    let client = ClientBuilder::new(reqwest::Client::new())
        // Trace HTTP requests. See the tracing crate to make use of these traces.
        .with(TracingMiddleware)
        // Retry failed requests.
        .with(RetryTransientMiddleware::new_with_policy(retry_policy))
        .build();
    run(client).await;
}

async fn run(client: ClientWithMiddleware) {
    client
        .get("https://truelayer.com")
        .header("foo", "bar")
        .send()
        .await
        .unwrap();
}

License

^{Licensed under either of Apache License, Version 2.0 or MIT license at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.}