OpenTelemetry Rust distro for Uptrace

[dependencies]
tokio = { version = "1", features = ["full"] }
tonic = { version = "0.13.1", features = ["tls-native-roots", "gzip"] }
opentelemetry = "0.30.0"
opentelemetry_sdk = { version = "0.30.0", features = ["rt-tokio"] }
opentelemetry-otlp = { version = "0.30.0", features = ["grpc-tonic", "gzip-tonic", "tls-roots", "trace"] }
opentelemetry-resource-detectors = "0.9"

use std::time::Duration;
use tonic::metadata::MetadataMap;
use opentelemetry::{global, KeyValue};
use opentelemetry::trace::Tracer;
use opentelemetry_otlp::{WithExportConfig, WithTonicConfig};
use opentelemetry_sdk::{
    propagation::TraceContextPropagator,
    trace::{BatchSpanProcessor, SdkTracerProvider},
    Resource,
};

fn init_tracer(dsn: String) -> Result<SdkTracerProvider, Box<dyn std::error::Error + Send + Sync>> {
    // Configure gRPC metadata with Uptrace DSN
    let mut metadata = MetadataMap::with_capacity(1);
    metadata.insert("uptrace-dsn", dsn.parse().unwrap());

    // Create OTLP span exporter
    let exporter = opentelemetry_otlp::SpanExporter::builder()
        .with_tonic()
        .with_tls_config(tonic::transport::ClientTlsConfig::new().with_native_roots())
        .with_endpoint("https://api.uptrace.dev:4317")
        .with_metadata(metadata)
        .with_timeout(Duration::from_secs(10))
        .build()?;

    // Build the tracer provider
    let provider = SdkTracerProvider::builder()
        .with_batch_exporter(exporter)
        .with_resource(Resource::new(vec![
            KeyValue::new("service.name", "myservice"),
            KeyValue::new("service.version", "1.0.0"),
        ]))
        .build();

    Ok(provider)
}

use opentelemetry::trace::{TraceContextExt, Tracer};
use opentelemetry::{global, KeyValue};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
    // Read Uptrace DSN from environment
    let dsn = std::env::var("UPTRACE_DSN").expect("UPTRACE_DSN not found");

    // Initialize tracer
    let provider = init_tracer(dsn)?;
    global::set_tracer_provider(provider.clone());

    let tracer = global::tracer("myservice");

    // Create a root span
    tracer.in_span("main-operation", |cx| {
        let span = cx.span();
        span.set_attribute(KeyValue::new("operation.type", "example"));

        // Create a child span
        tracer.in_span("child-operation", |cx| {
            let span = cx.span();
            span.set_attribute(KeyValue::new("http.method", "GET"));
            span.set_attribute(KeyValue::new("http.url", "http://localhost:8080/api"));
        });

        println!(
            "View trace: https://app.uptrace.dev/traces/{}",
            span.span_context().trace_id()
        );
    });

    // Flush and shutdown
    provider.force_flush()?;
    provider.shutdown()?;

    Ok(())
}

$ UPTRACE_DSN="<FIXME>" cargo run
View trace: https://app.uptrace.dev/traces/<trace_id>