feat(data-pipeline)!: export client-computed span stats as OTLP trace metrics

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

@@ -36,3 +36,20 @@ pub struct OtlpTraceConfig {
     #[allow(dead_code)]
     pub(crate) protocol: OtlpProtocol,
 }
+
+/// Parsed OTLP trace-metrics exporter configuration.
+#[derive(Clone, Debug)]
+pub struct OtlpMetricsConfig {
+    /// Full URL to POST metrics to (e.g. `http://localhost:4318/v1/metrics`).
+    pub endpoint_url: String,
+    /// Pre-validated HTTP headers to include in each request.
+    pub headers: HeaderMap,
+    /// Request timeout.
+    pub timeout: Duration,
+    /// Protocol (for future use; currently only HttpJson is supported).
+    #[allow(dead_code)]
+    pub(crate) protocol: OtlpProtocol,
+    /// When `true`, emit only OTel attributes; omit `dd.*`/`_dd.*` ones
+    /// (`DD_TRACE_OTEL_SEMANTICS_ENABLED`).
+    pub otel_trace_semantics_enabled: bool,
+}

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

@@ -5,30 +5,31 @@
 
 use super::config::OtlpTraceConfig;
 use crate::trace_exporter::error::{InternalErrorKind, RequestError, TraceExporterError};
+use http::HeaderMap;
 use libdd_capabilities::{HttpClientCapability, SleepCapability};
 use libdd_common::Endpoint;
 use libdd_trace_utils::send_with_retry::{
     send_with_retry, RetryBackoffType, RetryStrategy, SendWithRetryError,
 };
+use std::time::Duration;
 
-/// Max retries for OTLP export.
-const OTLP_MAX_RETRIES: u32 = 4;
-/// Initial backoff between retries (milliseconds).
+/// Max retries for OTLP export on transient failures.
+pub(crate) const OTLP_MAX_RETRIES: u32 = 4;
+/// No retries on shutdown to avoid a long backoff in the shutdown window.
+pub(crate) const OTLP_SHUTDOWN_MAX_RETRIES: u32 = 0;
 const OTLP_RETRY_DELAY_MS: u64 = 100;
 
-/// Send OTLP trace payload (JSON bytes) to the configured endpoint with retries.
-///
-/// Uses [`send_with_retry`] for consistent retry behaviour and observability across exporters.
-///
-/// `test_token` is forwarded as `X-Datadog-Test-Session-Token` when set, enabling snapshot tests
-/// against the Datadog test agent's OTLP endpoint.
-pub async fn send_otlp_traces_http<C: HttpClientCapability + SleepCapability>(
+/// POST an OTLP HTTP/JSON payload to `endpoint_url`; `test_token` enables snapshot tests.
+pub(crate) async fn send_otlp_http<C: HttpClientCapability + SleepCapability>(
     capabilities: &C,
-    config: &OtlpTraceConfig,
+    endpoint_url: &str,
+    config_headers: &HeaderMap,
+    timeout: Duration,
     test_token: Option<&str>,
     json_body: Vec<u8>,
+    max_retries: u32,
 ) -> Result<(), TraceExporterError> {
-    let url = libdd_common::parse_uri(&config.endpoint_url).map_err(|e| {
+    let url = libdd_common::parse_uri(endpoint_url).map_err(|e| {
         TraceExporterError::Internal(InternalErrorKind::InvalidWorkerState(format!(
             "Invalid OTLP endpoint URL: {}",
             e
@@ -37,11 +38,11 @@ pub async fn send_otlp_traces_http<C: HttpClientCapability + SleepCapability>(
 
     let target = Endpoint {
         url,
-        timeout_ms: config.timeout.as_millis() as u64,
+        timeout_ms: timeout.as_millis() as u64,
         ..Endpoint::default()
     };
 
-    let mut headers = config.headers.clone();
+    let mut headers = config_headers.clone();
     headers.insert(
         http::header::CONTENT_TYPE,
         libdd_common::header::APPLICATION_JSON,
@@ -56,7 +57,7 @@ pub async fn send_otlp_traces_http<C: HttpClientCapability + SleepCapability>(
     }
 
     let retry_strategy = RetryStrategy::new(
-        OTLP_MAX_RETRIES,
+        max_retries,
         OTLP_RETRY_DELAY_MS,
         RetryBackoffType::Exponential,
         None,
@@ -68,6 +69,30 @@ pub async fn send_otlp_traces_http<C: HttpClientCapability + SleepCapability>(
     }
 }
 
+/// Send OTLP trace payload (JSON bytes) to the configured endpoint with retries.
+///
+/// Uses [`send_with_retry`] for consistent retry behaviour and observability across exporters.
+///
+/// `test_token` is forwarded as `X-Datadog-Test-Session-Token` when set, enabling snapshot tests
+/// against the Datadog test agent's OTLP endpoint.
+pub async fn send_otlp_traces_http<C: HttpClientCapability + SleepCapability>(
+    capabilities: &C,
+    config: &OtlpTraceConfig,
+    test_token: Option<&str>,
+    json_body: Vec<u8>,
+) -> Result<(), TraceExporterError> {
+    send_otlp_http(
+        capabilities,
+        &config.endpoint_url,
+        &config.headers,
+        config.timeout,
+        test_token,
+        json_body,
+        OTLP_MAX_RETRIES,
+    )
+    .await
+}
+
 async fn map_send_error(err: SendWithRetryError) -> TraceExporterError {
     match err {
         SendWithRetryError::Http(response, _) => {