RequestId as Response Header

[vbrandl]

I want to add the RequestId to every response as a header x-request-id.

What would be the easiest way to do that? Do I have to implement a custom middleware? Would this be a good feature addition to tracing-actix-web directly?

[LukeMathWalker]

A very simple custom middleware should do the job.
This is not a feature I'm planning to add right now.

[vbrandl]

Ok it was easier than expected. The following code adds the header, if you want to add it to your examples:

App::new()
    .wrap_fn(|req, srv| {
        let request_id = req.extensions().get::<RequestId>().copied();
        let fut = srv.call(req);
        async move {
            let mut res = fut.await?;
            if let Some(request_id) = request_id {
                res.headers_mut().insert(
                    HeaderName::from_static("x-request-id"),
                    // this unwrap never fails, since UUIDs are valid ASCII strings
                    HeaderValue::from_str(&request_id.to_string()).unwrap(),
                    );
            }
            Ok(res)
        }
    })

[LukeMathWalker]

Feel free to submit a PR with the example 👍🏻