feat: add example app to debug issue with propagation

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "dd-trace",
     "dd-trace-propagation",
     "dd-trace-sampling",
+    "dd-trace-examples",
 ]
 
 # https://doc.rust-lang.org/cargo/reference/resolver.html#feature-resolver-version-2
@@ -38,7 +39,9 @@ opentelemetry_sdk = { version = "0.30.0", features = [
 opentelemetry = { version = "0.30.0", features = [
     "trace",
 ], default-features = false }
-opentelemetry-semantic-conventions = { version = "0.30.0", features = ["semconv_experimental"] }
+opentelemetry-semantic-conventions = { version = "0.30.0", features = [
+    "semconv_experimental",
+] }
 tokio = { version = "1.44.1" }
 rand = { version = "0.8", features = ["small_rng"] }
 

datadog-opentelemetry/src/span_exporter.rs

@@ -596,6 +596,7 @@ impl TraceExporterWorker {
                 )
             })
             .collect();
+        dbg!(&trace_chunks);
         match self.trace_exporter.send_trace_chunks(trace_chunks) {
             Ok(agent_response) => {
                 self.handle_agent_response(agent_response);

datadog-opentelemetry/src/span_processor.rs

@@ -40,6 +40,7 @@ struct Trace {
     tags: Option<HashMap<String, String>>,
 }
 
+#[derive(Debug)]
 pub(crate) struct TracePropagationData {
     pub sampling_decision: Option<SamplingDecision>,
     pub origin: Option<String>,
@@ -403,6 +404,7 @@ impl DatadogSpanProcessor {
     /// If [`Trace`] contains origin, tags or sampling_decision add them as attributes of the root
     /// span
     fn add_trace_propagation_data(&self, mut trace: Trace) -> Vec<SpanData> {
+        dbg!(&trace);
         let origin = trace.origin.unwrap_or_default();
 
         for span in trace.finished_spans.iter_mut() {
@@ -427,6 +429,7 @@ impl DatadogSpanProcessor {
                     "_sampling_priority_v1",
                     sampling_decision.priority.into_i8() as i64,
                 ));
+                dbg!(&sampling_decision, u64::from_be_bytes(span.span_context.span_id().to_bytes()));
 
                 span.attributes.push(KeyValue::new(
                     SAMPLING_DECISION_MAKER_TAG_KEY,
@@ -454,6 +457,7 @@ impl opentelemetry_sdk::trace::SpanProcessor for DatadogSpanProcessor {
 
         if parent_ctx.span().span_context().is_remote() {
             let propagation_data = self.get_remote_propagation_data(span, parent_ctx);
+            dbg!(&propagation_data);
             self.registry
                 .register_span(trace_id, span_id, propagation_data);
         } else if !parent_ctx.has_active_span() {

dd-trace-examples/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+name = "dd-trace-examples"
+rust-version.workspace = true
+edition.workspace = true
+version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description.workspace = true
+
+[dependencies]
+# Datadog OpenTelemetry
+datadog-opentelemetry = { path = "../datadog-opentelemetry" }
+dd-trace = { path = "../dd-trace" }
+
+# Tracing ecosystem
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+tracing-opentelemetry = "0.31"
+
+# HTTP server
+axum = "0.7"
+tokio = { version = "1.44.1", features = ["full"] }
+
+# OpenTelemetry
+opentelemetry = { version = "0.30.0", features = ["trace"] }
+opentelemetry_sdk = { version = "0.30.0", features = ["trace"] }
+opentelemetry-http = { version = "0.30.0" }
+
+# Utilities
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+tower = "0.4"
+tower-http = { version = "0.5", features = ["cors", "trace"] }
+rand = "0.8"