feat(data-pipeline): add fork-safe OTLP gRPC trace transport

libdd-data-pipeline/Cargo.toml

@@ -51,8 +51,14 @@ libdd-tinybytes = { version = "1.1.2", path = "../libdd-tinybytes", features = [
 web-time = "1"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
-tokio = { version = "1.23", features = ["time", "test-util"], default-features = false }
+tokio = { version = "1.23", features = ["time", "test-util", "net"], default-features = false }
 libdd-capabilities-impl = { version = "4.0.0", path = "../libdd-capabilities-impl", default-features = false }
+# OTLP gRPC transport: a custom GrpcService over hyper h2c. tonic's transport
+# (hyper/tokio/socket2) does not build for wasm32, so the whole gRPC path is gated off.
+tonic = { version = "0.14", default-features = false }
+prost = "0.14.1"
+hyper = { workspace = true, features = ["client", "http2"] }
+hyper-util = { workspace = true, features = ["tokio"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 getrandom = { version = "0.2", features = ["js"] }
@@ -88,6 +94,7 @@ tokio = { version = "1.23", features = [
 duplicate = "2.0.1"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+h2 = "0.4"
 zstd = { version = "0.13", default-features = false }
 
 [target.'cfg(target_arch = "wasm32")'.dev-dependencies]

libdd-data-pipeline/src/otlp/config.rs

@@ -85,6 +85,19 @@ pub struct OtlpTraceConfig {
     pub otel_trace_semantics_enabled: bool,
 }
 
+/// Per-request OTLP gRPC trace exporter configuration.
+// Not yet wired to the trace exporter's send loop; exercised by tests only.
+#[allow(dead_code)]
+#[derive(Clone, Debug)]
+pub struct OtlpGrpcTraceConfig {
+    /// Custom key-value pairs forwarded as gRPC request metadata.
+    pub headers: Vec<(String, String)>,
+    /// Per-request timeout.
+    pub timeout: Duration,
+    /// When `true`, omit DD-specific per-span attributes from the payload.
+    pub otel_trace_semantics_enabled: bool,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;