reqwest-middleware/reqwest-tracing/README.md

reqwest-tracing

Opentracing middleware implementation for reqwest-middleware.

Overview

Attach TracingMiddleware to your client to automatically trace HTTP requests:

# Cargo.toml
# ...
[dependencies]
opentelemetry = "0.18"
reqwest = "0.11"
reqwest-middleware = "0.1.1"
reqwest-retry = "0.1.1"
reqwest-tracing = { version = "0.3.1", features = ["opentelemetry_0_18"] }
tokio = { version = "1.12.0", features = ["macros", "rt-multi-thread"] }
tracing = "0.1"
tracing-opentelemetry = "0.18"
tracing-subscriber = "0.3"
task-local-extensions = "0.1.4"

use reqwest_tracing::{default_on_request_end, reqwest_otel_span, ReqwestOtelSpanBackend, TracingMiddleware};
use opentelemetry::sdk::export::trace::stdout;
use reqwest::{Request, Response};
use reqwest_middleware::{ClientBuilder, Result};
use std::time::Instant;
use task_local_extensions::Extensions;
use tracing::Span;
use tracing_subscriber::layer::SubscriberExt;
use tracing_subscriber::Registry;

pub struct TimeTrace;

impl ReqwestOtelSpanBackend for TimeTrace {
    fn on_request_start(req: &Request, extension: &mut Extensions) -> Span {
        extension.insert(Instant::now());
        reqwest_otel_span!(name="example-request", req, time_elapsed = tracing::field::Empty)
    }

    fn on_request_end(span: &Span, outcome: &Result<Response>, extension: &mut Extensions) {
        let time_elapsed = extension.get::<Instant>().unwrap().elapsed().as_millis() as i64;
        default_on_request_end(span, outcome);
        span.record("time_elapsed", &time_elapsed);
    }
}

#[tokio::main]
async fn main() {
    let tracer = stdout::new_pipeline().install_simple();
    let telemetry = tracing_opentelemetry::layer().with_tracer(tracer);
    let subscriber = Registry::default().with(telemetry);
    tracing::subscriber::set_global_default(subscriber).unwrap();

    run().await;
}

async fn run() {
    let client = ClientBuilder::new(reqwest::Client::new())
        .with(TracingMiddleware::<TimeTrace>::new())
        .build();

    client.get("https://truelayer.com").send().await.unwrap();
}

$ cargo run
SpanData { span_context: SpanContext { trace_id: ...

See the tracing crate for more information on how to set up a tracing subscriber to make use of the spans.

How to install

Add reqwest-tracing to your dependencies. Optionally enable opentelemetry integration by enabling an opentelemetry version feature:

[dependencies]
# ...
reqwest-tracing = { version = "0.3.1", features = ["opentelemetry_0_18"] }

Available opentelemetry features are opentelemetry_0_18, opentelemetry_0_17, opentelemetry_0_16, opentelemetry_0_15, opentelemetry_0_14 and opentelemetry_0_13.

License

^{Licensed under either of Apache License, Version 2.0 or MIT license at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.}