Function main

examples/opentelemetry-tracing/src/main.rs:18–46

()

#[tokio::main]
async fn main() -> Result<(), BoxError> {
    // Set up OpenTelemetry tracer provider that writes spans to stdout for debugging purposes
    let exporter = opentelemetry_stdout::SpanExporter::default();
    let tracer_provider = trace::SdkTracerProvider::builder()
        .with_batch_exporter(exporter)
        .build();

    // Set up link between OpenTelemetry and tracing crate
    tracing_subscriber::registry()
        .with(tracing_opentelemetry::OpenTelemetryLayer::new(
            tracer_provider.tracer("my-app"),
        ))
        .init();

    // Initialize the Lambda runtime and add OpenTelemetry tracing
    let runtime = Runtime::new(service_fn(echo)).layer(
        // Create a tracing span for each Lambda invocation
        OtelLayer::new(|| {
            // Make sure that the trace is exported before the Lambda runtime is frozen
            if let Err(err) = tracer_provider.force_flush() {
                eprintln!("Error flushing traces: {err:#?}");
            }
        })
        // Set the "faas.trigger" attribute of the span to "pubsub"
        .with_trigger(OpenTelemetryFaasTrigger::PubSub),
    );
    runtime.run().await?;
    Ok(())
}