refactor(o11y): compose otel layer

crates/synd_o11y/src/lib.rs

@@ -4,6 +4,9 @@ pub mod health_check;
 pub mod opentelemetry;
 pub mod tracing_subscriber;
 
+pub use opentelemetry::OpenTelemetryGuard;
+pub use tracing_subscriber::opentelemetry_layer;
+
 /// Request id key for opentelemetry baggage
 pub const REQUEST_ID_KEY: &str = "request.id";
 

crates/synd_o11y/src/tracing_subscriber/mod.rs

@@ -1,4 +1,26 @@
+use std::borrow::Cow;
+
+use tracing::Subscriber;
+use tracing_subscriber::{registry::LookupSpan, Layer};
+
 pub mod audit;
 pub mod otel_log;
 pub mod otel_metrics;
 pub mod otel_trace;
+
+pub fn opentelemetry_layer<S>(
+    endpoint: impl Into<String>,
+    service_name: impl Into<Cow<'static, str>>,
+    service_version: impl Into<Cow<'static, str>>,
+    trace_sampler_ratio: f64,
+) -> impl Layer<S>
+where
+    S: Subscriber + for<'span> LookupSpan<'span>,
+{
+    let endpoint = endpoint.into();
+    let resource = crate::opentelemetry::resource(service_name, service_version);
+
+    otel_trace::layer(endpoint.clone(), resource.clone(), trace_sampler_ratio)
+        .and_then(otel_metrics::layer(endpoint.clone(), resource.clone()))
+        .and_then(otel_log::layer(endpoint, resource))
+}