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.

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

[tokio::main]

async fn main() -> Result<(), axum::BoxError> { // very opinionated init of tracing, look as is source to make your own inittracingopentelemetry::tracingsubscriberext::init_subscribers()?;

let app = app();
// run it
let addr = &"0.0.0.0:3000".parse::<SocketAddr>()?;
tracing::warn!("listening on {}", addr);
axum::Server::bind(&addr)
    .serve(app.into_make_service())
    .with_graceful_shutdown(shutdown_signal())
    .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 }

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

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

Compatibility

| axum | axum-tracing-opentelemetry | |------|----------------------------| | 0.6 | latest - 0.6 | | 0.5 | 0.1 - 0.5 |

Changelog - History

0.12

• 💥 upgrade opentelemetry attributes to follow semantic 1.22
• 💥 extract tools, tonic,... into separate crates [init-tracing-opentelemetry], [tonic-tracing-opentelemetry], [tracing-opentelemetry-instrumentation-sdk], without re-export and features
• 💥 remove trace_id from attributes (opnetelemetry) and field in trace (log,...) on creation because the previous workaround created invalid states in some context
• deprecate factory opentelemetry_tracing_layer, response_with_trace_layer
• full rewrite without tower-http/Tracing

0.11

• upgrade to opentelemetry 0.19

0.10

• 💥 default configuration for otlp Sampler is no longer hardcoded to always_on, but read environment variables OTEL_TRACES_SAMPLER, OTEL_TRACES_SAMPLER_ARG
• ✨ provide opinionated tracing_subscriber_ext
• ✨ log under target otel::setup detected configuration by otel setup tools
• ✨ add a axum layer for gRPC (#36) (wip)

0.9

• add DetectResource builder to help detection for Resource Semantic Conventions | OpenTelemetry

0.8

• add init_propagator to configure the global propagator based on content of the env variable OTEL_PROPAGATORS

0.7

• add a layerresponse_with_trace_layer to have traceparent injected into response
• improve discovery of otlp configuration based on OTEL_EXPORTER_OTLP_TRACES_ENDPOINT, OTEL_EXPORTER_OTLP_ENDPOINT, OTEL_EXPORTER_OTLP_TRACES_PROTOCOL, OTEL_EXPORTER_OTLP_PROTOCOL

0.6

• upgrade to axum 0.6

0.5

• upgrade to opentelemetry 0.18
• breaking change: upgrade opentelemetry-jaeger to 0.17 (switch from PipelineBuiler to AgentPipeline)

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