tower VS tower-http

This question is partially inspired by this PR which is kinda trying to do the same thing.

dd-trace-layer is a middleware for sending Datadog's trace. It's based on Tower and OpenTelemetry Rust.

I'm pretty sure that GCP's APIs (unlike AWS, which uses Smithy for very genuinely, very good reason) are defined using Protobuf and can be communicated with over gRPC, which means that you don't need to bind via cxx to GCP's C++ APIs. Take a look at this example using Tonic. If you're to use Tonic, you'll also be able to use Tower's middleware (main crate, http-specific) to implement retries, timeouts, tracing, and all the other things you need to be production-ready.

#[derive(Clone)] struct MyMiddleware { inner: S, } impl Service> for MyMiddleware where S: Service, Response = Response> + Clone + Send + 'static, S::Future: Send + 'static, { type Response = S::Response; type Error = S::Error; type Future = BoxFuture<'static, Result>; fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll> { self.inner.poll_ready(cx) } fn call(&mut self, mut req: Request) -> Self::Future { println!("before"); // best practice is to clone the inner service like this // see https://github.com/tower-rs/tower/issues/547 for details let clone = self.inner.clone(); let mut inner = std::mem::replace(&mut self.inner, clone); Box::pin(async move { let res: Response = inner.call(req).await?; println!("after"); Ok(res) }) } } fn main() { let app = Router::new() .route("/", get(|| async { /* ... */ })) .layer(layer_fn(|inner| MyMiddleware { inner })); }

For this tutorial, we're going to use apalis to run cron jobs in an async context. We will also look at how to decorate our jobs with tower middleware allowing us to unlock features like retries, prometheus, sentry etc

So I have now had a look at Axum and think I will give it a try. In the readme in the repository it says something about tower or tower::Service and tonic, what exactly is that? I do not understand that yet.

Better compatibility with tower ecosystem.

ratpack is idealized in the simplicity of the sinatra (ruby) framework in its goal, and attempts to be an alternative to other async HTTP frameworks such as tower, warp, axum, and tide.

i would browse the standard library, tower, nom, or my own bitvec to see layout and trait/record separation. in particular, std::io and std::net may be of use: io::Read and io::Write are pervasive examples of implementing unixy file-descriptor-like behavior in the type system

We're not there yet. I keep an eye on Tower which looks promising to build on top of. And I keep an eye on MoonZoon (full stack framework, unashamedly opinionated!).

If your goal is specifically a web proxy, you also might want to take a look at async Rust such as hyper and tower-http, which are part of the tokio ecosystem. (But spawning threads could be just fine too, if it's not super performance-sensitive.)

here's the issue for more detailed info: https://github.com/tower-rs/tower-http/issues/136

tower-http has several simple middleware if you're looking for more examples. AddExtension, SetRequestHeader and SetResponseHeader are good places to start. If you want to see something that goes all-in then Trace is probably the most complex middleware in tower-http.

You could also look at https://github.com/tower-rs/tower-http which is a work in progress set of HTTP specific middlewares for tower. It also has examples that uses hyper as the HTTP server.