axum-tracing-opentelemetry

Middlewares and tools 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

For examples, you can look at:

• the examples folder
• davidB/sandboxaxumobservability: Sandbox to experiment axum and observability. This example shows also propagation of the trace between tracing span and service (via reqwest).

```rust //... use axumtracingopentelemetry::opentelemetrytracinglayer;

fn inittracing() { use axumtracingopentelemetry::{ makeresource, otlp, //stdio, };

let otel_rsrc = make_resource(env!("CARGO_PKG_NAME"), env!("CARGO_PKG_VERSION"));
let otel_tracer = otlp::init_tracer(otel_rsrc, otlp::identity).expect("setup of Tracer");
// let otel_tracer =
//     stdio::init_tracer(otel_rsrc, stdio::identity, stdio::WriteNoWhere::default())
//         .expect("setup of Tracer");
let otel_layer = tracing_opentelemetry::layer().with_tracer(otel_tracer);

let subscriber = tracing_subscriber::registry()
    //...
    .with(otel_layer);
tracing::subscriber::set_global_default(subscriber).unwrap();

}

[tokio::main]

async fn main() -> Result<(), Box> { inittracing(); let app = app(); // run it let addr = &"0.0.0.0:3000".parse::()?; tracing::warn!("listening on {}", addr); axum::Server::bind(&addr) .serve(app.intomakeservice()) .withgracefulshutdown(shutdownsignal()) .await?; Ok(()) }

fn app() -> Router { // build our application with a route Router::new() .route("/", get(health)) // request processed inside span // opentelemetrytracinglayer setup TraceLayer, that is provided by tower-http so you have to add that as a dependency. .layer(opentelemetrytracinglayer()) .route("/health", get(health)) // request processed without span / trace }

async fn shutdownsignal() { //... opentelemetry::global::shutdowntracer_provider(); } ```

To retrieve the current trace_id (eg to add it into error message (as header or attributes))

rust let trace_id = axum_tracing_opentelemetry::find_current_trace_id(); json!({ "error" : "xxxxxx", "trace_id": trace_id})

History

0.4

• allow customization of tracer
• add tracer to export on stdout or stderr
• add tracer to export to nowhere (like /dev/null) to allow to have trace_id and the opentelemetry span & metadata on log and http response (without collector)

0.3

• Allow customization of exporter pipeline
• Fix name of the root span (#6)

0.2

• First public release as a crate

0.1

• Code originally created at part of axum-extra Add OpenTelemetry middleware by davidpdrsn · Pull Request #769 · tokio-rs/axum
• Code copied and modified as part of davidB/sandboxaxumobservability: Sandbox to experiment axum and observability
• Published as a standalone crate with OK from original author