use reqwest::header::{HeaderName, HeaderValue}; use reqwest::Request; use std::str::FromStr; use tracing::Span; #[cfg(feature = "opentelemetry_0_13")] use opentelemetry_0_13_pkg as opentelemetry; #[cfg(feature = "opentelemetry_0_14")] use opentelemetry_0_14_pkg as opentelemetry; #[cfg(feature = "opentelemetry_0_15")] use opentelemetry_0_15_pkg as opentelemetry; #[cfg(feature = "opentelemetry_0_16")] use opentelemetry_0_16_pkg as opentelemetry; #[cfg(feature = "opentelemetry_0_17")] use opentelemetry_0_17_pkg as opentelemetry; #[cfg(feature = "opentelemetry_0_18")] use opentelemetry_0_18_pkg as opentelemetry; #[cfg(feature = "opentelemetry_0_13")] pub use tracing_opentelemetry_0_12_pkg as tracing_opentelemetry; #[cfg(feature = "opentelemetry_0_14")] pub use tracing_opentelemetry_0_13_pkg as tracing_opentelemetry; #[cfg(feature = "opentelemetry_0_15")] pub use tracing_opentelemetry_0_14_pkg as tracing_opentelemetry; #[cfg(feature = "opentelemetry_0_16")] pub use tracing_opentelemetry_0_16_pkg as tracing_opentelemetry; #[cfg(feature = "opentelemetry_0_17")] pub use tracing_opentelemetry_0_17_pkg as tracing_opentelemetry; #[cfg(feature = "opentelemetry_0_18")] pub use tracing_opentelemetry_0_18_pkg as tracing_opentelemetry; use opentelemetry::global; use opentelemetry::propagation::Injector; use tracing_opentelemetry::OpenTelemetrySpanExt; /// Injects the given OpenTelemetry Context into a reqwest::Request headers to allow propagation downstream. pub fn inject_opentelemetry_context_into_request(mut request: Request) -> Request { let context = Span::current().context(); global::get_text_map_propagator(|injector| { injector.inject_context(&context, &mut RequestCarrier::new(&mut request)) }); request } // "traceparent" => https://www.w3.org/TR/trace-context/#trace-context-http-headers-format /// Injector used via opentelemetry propagator to tell the extractor how to insert the "traceparent" header value /// This will allow the propagator to inject opentelemetry context into a standard data structure. Will basically /// insert a "traceparent" string value "{version}-{trace_id}-{span_id}-{trace-flags}" of the spans context into the headers. /// Listeners can then re-hydrate the context to add additional spans to the same trace. struct RequestCarrier<'a> { request: &'a mut Request, } impl<'a> RequestCarrier<'a> { pub fn new(request: &'a mut Request) -> Self { RequestCarrier { request } } } impl<'a> Injector for RequestCarrier<'a> { fn set(&mut self, key: &str, value: String) { let header_name = HeaderName::from_str(key).expect("Must be header name"); let header_value = HeaderValue::from_str(&value).expect("Must be a header value"); self.request.headers_mut().insert(header_name, header_value); } } #[cfg(test)] mod test { use super::*; use crate::TracingMiddleware; use opentelemetry::sdk::propagation::TraceContextPropagator; use reqwest_middleware::ClientBuilder; use tracing::{info_span, Instrument, Level}; #[cfg(any( feature = "opentelemetry_0_13", feature = "opentelemetry_0_14", feature = "opentelemetry_0_15" ))] use tracing_subscriber_0_2::{filter, layer::SubscriberExt, Registry}; #[cfg(not(any( feature = "opentelemetry_0_13", feature = "opentelemetry_0_14", feature = "opentelemetry_0_15" )))] use tracing_subscriber_0_3::{filter, layer::SubscriberExt, Registry}; use wiremock::{matchers::any, Mock, MockServer, ResponseTemplate}; #[tokio::test] async fn tracing_middleware_propagates_otel_data_even_when_the_span_is_disabled() { let tracer = opentelemetry::sdk::export::trace::stdout::new_pipeline() .with_writer(std::io::sink()) .install_simple(); let telemetry = tracing_opentelemetry::layer().with_tracer(tracer); let subscriber = Registry::default() .with(filter::Targets::new().with_target("reqwest_tracing::otel::test", Level::DEBUG)) .with(telemetry); tracing::subscriber::set_global_default(subscriber).unwrap(); global::set_text_map_propagator(TraceContextPropagator::new()); // Mock server - sends all request headers back in the response let server = MockServer::start().await; Mock::given(any()) .respond_with(|req: &wiremock::Request| { req.headers .iter() .fold(ResponseTemplate::new(200), |resp, (k, v)| { resp.append_header(k.clone(), v.clone()) }) }) .mount(&server) .await; let client = ClientBuilder::new(reqwest::Client::new()) .with(TracingMiddleware::default()) .build(); let resp = client .get(server.uri()) .send() .instrument(info_span!("some_span")) .await .unwrap(); assert!(resp.headers().contains_key("traceparent")); } }