Expose Hyper Client

[borchero]

I'm currently using reqwest to make requests to an API using mutual TLS.

For some endpoints, more advanced networking features are required and I need to fall back to using a Hyper client. However, it is hard to establish mutual TLS using Hyper and rustls and, furthermore, it's a little undesirable to manage two distinct Hyper clients (as reqwest is backed by one anyway).

It would be great if reqwest's client would expose a method granting access to the underlying Hyper client.

[seanmonstar]

What part of a hyper::Client would you need access to?

[borchero]

Basically, I wanted to get access to .inner.hyper, but I noticed I need to expose too many types that are not public.

I now went with the following public function that I added to the client. It does its job but I'm not sure if it should be part of this crate (although I'd love to not use my own fork):

pub fn execute_hyper(
    &self,
    builder: http::request::Builder,
    body: impl Into<super::body::Body>,
) -> Result<hyper::client::ResponseFuture, http::Error> {
    let request = builder.body(body.into().into_stream())?;
    return Ok(self.inner.hyper.request(request));
}

[seanmonstar]

What does that give you that isn't possible with the reqwest::Client? I'm trying to understand the intent, to see if there's another solution besides just opening up private methods.

[borchero]

Basically, I need to hijack the underlying TCP stream (I'm interfacing with the Docker API and this is required for some interactive calls). Using Hyper, I can schedule the request and then get access to the TCP stream using the Upgraded type.

This looks something like that:

let request = hyper::Request::builder()
    .method(hyper::Method::POST)
    .uri(format!("http://localhost:2375/exec/{}/start", id))
    .header(hyper::header::CONTENT_TYPE, "application/json")
    .header(hyper::header::CONNECTION, "Upgrade")
    .header(hyper::header::UPGRADE, "tcp")
    .body(hyper::Body::from(body))?;

let client = hyper::Client::new();
let response = client.request(request).await?;
let mut upgraded = response.into_body().on_upgrade().await?;
// `upgraded` is now `AsyncRead` and `AsyncWrite`

I doubt that reqwest currently enables doing something like that and I'm not sure if gaining access to the underlying TCP connection is a common use case.

[seanmonstar]

I see, so you want to do HTTP upgrades. That's not currently exposed in reqwest, though it's probably not difficult to do so without opening up the internals.

…

On Wed, Sep 30, 2020, 10:24 AM Oliver Borchert ***@***.***> wrote: Basically, I need to hijack the underlying TCP stream (I'm interfacing with the Docker API and this is required for some interactive calls). Using Hyper, I can schedule the request and then get access to the TCP stream using the Upgraded <https://docs.rs/hyper/0.13.8/hyper/upgrade/struct.Upgraded.html> type. This looks something like that: let request = hyper::Request::builder() .method(hyper::Method::POST) .uri(format!("http://localhost:2375/exec/{}/start", id)) .header(hyper::header::CONTENT_TYPE, "application/json") .header(hyper::header::CONNECTION, "Upgrade") .header(hyper::header::UPGRADE, "tcp") .body(hyper::Body::from(body))?; let client = hyper::Client::new();let response = client.request(request).await?;let mut upgraded = response.into_body().on_upgrade().await?;// `upgraded` is now `AsyncRead` and `AsyncWrite` I doubt that reqwest currently enables doing something like that and I'm not sure if gaining access to the underlying TCP connection is a common use case. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1045 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAMSFYD4WGX7HYYTSNRBX3SINSVHANCNFSM4R7FVLVA> .

[borchero]

Yes, exactly. I'm not too familiar with reqwest's internals at the moment, but if you think this would be nice to have in reqwest, I might familiarize myself a bit more with it in the coming days and might open a PR soon.

[luqmana]

HTTP Upgrade support has landed with #1376:

reqwest/tests/upgrade.rs

Lines 33 to 50 in 61474f4

	let res = reqwest::Client::builder()
	.build()
	.unwrap()
	.get(format!("http://{}", server.addr()))
	.header(http::header::CONNECTION, "upgrade")
	.header(http::header::UPGRADE, "foobar")
	.send()
	.await
	.unwrap();
	assert_eq!(res.status(), http::StatusCode::SWITCHING_PROTOCOLS);
	let mut upgraded = res.upgrade().await.unwrap();
	upgraded.write_all(b"foo=bar").await.unwrap();
	let mut buf = vec![];
	upgraded.read_to_end(&mut buf).await.unwrap();
	assert_eq!(buf, b"bar=foo");