Distributed tracing of outgoing request

[indietyp]

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I have several services which are written in Rust and communicate over HTTP APIs, all these services are going to be instrumented via Sentry. I am trying to setup distributed tracing among them, but have found out that the sentry SDK currently does not support outgoing requests.

I therefore have two questions:

Is support for popular client libraries such as reqwest planned?

I am aware that I "only" need to send the sentry-trace and baggage HTTP headers, which means that I (in theory) would be able to implement this quite easily myself, but I haven't found any documentation about how to obtain these values. What do these headers actually contain and how can I obtain these values to attach them to my HTTP requests?

Thanks so much in advance!

[Swatinem]

With Rust, it is not really possible to hook into this automatically, and thus has to be done manually, like so:

        if let Some(span) = sentry::configure_scope(|scope| scope.get_span()) {
            for (k, v) in span.iter_headers() {
                request = request.header(k, v);
            }
        }

(from https://github.com/getsentry/symbolicator/blob/344e90f8c4aa07fe9bd1a311dd4320f33b7ee8f8/crates/symbolicator-service/src/services/download/sentry.rs#L187-L191 )

It might be possible to add a convenience method via an extension trait, for example builder.propagate_sentry_trace() or something…