reqwest_tracing/
middleware.rs

1use http::Extensions;
2use reqwest::{Request, Response};
3use reqwest_middleware::{Middleware, Next, Result};
4use tracing::Instrument;
5
6use crate::{DefaultSpanBackend, ReqwestOtelSpanBackend};
7
8/// Middleware for tracing requests using the current Opentelemetry Context.
9pub struct TracingMiddleware<S: ReqwestOtelSpanBackend> {
10    span_backend: std::marker::PhantomData<S>,
11}
12
13impl<S: ReqwestOtelSpanBackend> TracingMiddleware<S> {
14    pub fn new() -> TracingMiddleware<S> {
15        TracingMiddleware {
16            span_backend: Default::default(),
17        }
18    }
19}
20
21impl<S: ReqwestOtelSpanBackend> Clone for TracingMiddleware<S> {
22    fn clone(&self) -> Self {
23        Self::new()
24    }
25}
26
27impl Default for TracingMiddleware<DefaultSpanBackend> {
28    fn default() -> Self {
29        TracingMiddleware::new()
30    }
31}
32
33#[cfg_attr(not(target_arch = "wasm32"), async_trait::async_trait)]
34#[cfg_attr(target_arch = "wasm32", async_trait::async_trait(?Send))]
35impl<ReqwestOtelSpan> Middleware for TracingMiddleware<ReqwestOtelSpan>
36where
37    ReqwestOtelSpan: ReqwestOtelSpanBackend + Sync + Send + 'static,
38{
39    async fn handle(
40        &self,
41        req: Request,
42        extensions: &mut Extensions,
43        next: Next<'_>,
44    ) -> Result<Response> {
45        let request_span = ReqwestOtelSpan::on_request_start(&req, extensions);
46
47        let outcome_future = async {
48            #[cfg(any(
49                feature = "opentelemetry_0_20",
50                feature = "opentelemetry_0_21",
51                feature = "opentelemetry_0_22",
52                feature = "opentelemetry_0_23",
53                feature = "opentelemetry_0_24",
54                feature = "opentelemetry_0_25",
55                feature = "opentelemetry_0_26",
56                feature = "opentelemetry_0_27",
57                feature = "opentelemetry_0_28",
58            ))]
59            let req = if extensions.get::<crate::DisableOtelPropagation>().is_none() {
60                // Adds tracing headers to the given request to propagate the OpenTelemetry context to downstream revivers of the request.
61                // Spans added by downstream consumers will be part of the same trace.
62                crate::otel::inject_opentelemetry_context_into_request(req)
63            } else {
64                req
65            };
66
67            // Run the request
68            let outcome = next.run(req, extensions).await;
69            ReqwestOtelSpan::on_request_end(&request_span, &outcome, extensions);
70            outcome
71        };
72
73        outcome_future.instrument(request_span.clone()).await
74    }
75}
reqwest_tracing/middleware.rs

reqwest_tracing/
middleware.rs
