axum-tracing-opentelemetry

Middlewares to integrate axum + tracing + opentelemetry.

• Read OpenTelemetry header from incoming request
• Start a new trace if no trace found in the incoming request
• Trace is attached into tracing'span
• OpenTelemetry Span is created on close of the tracing's span (behavior from [tracing-opentelemetry])

For examples, you can look at the examples folder.

//...
use axum_tracing_opentelemetry::middleware::{OtelAxumLayer, OtelInResponseLayer};

#[tokio::main]
async fn main() -> Result<(), axum::BoxError> {
    // very opinionated init of tracing, look at the source to make your own
    let _guard = init_tracing_opentelemetry::tracing_subscriber_ext::init_subscribers()?;

    let app = app();
    // run it
    let addr = &"0.0.0.0:3000".parse::<SocketAddr>()?;
    tracing::warn!("listening on {}", addr);
    let listener = tokio::net::TcpListener::bind(addr).await?;
    axum::serve(listener, app.into_make_service()).await?;
    Ok(())
}

fn app() -> Router {
    Router::new()
        .route("/", get(index)) // request processed inside span
        // include trace context as header into the response
        .layer(OtelInResponseLayer::default())
        //start OpenTelemetry trace on incoming request
        .layer(OtelAxumLayer::default())
        .route("/health", get(health)) // request processed without span / trace
}

For more info about how to initialize, you can look at crate init-tracing-opentelemetry or tracing-opentelemetry.

Changelog - History

CHANGELOG.md