fix(otel): avoid tracing otlp connections [backport 3.17] (#15082)

Backport c426d0f from #14984 to 3.17.

## Description

Prevents OpenTelemetry OTLP exporters from being traced by ddtrace to
avoid circular instrumentation.

## Problem

When OpenTelemetry metrics/logs exporters send data, ddtrace was
instrumenting these internal connections, creating unwanted spans and
potential circular tracing issues.

## Solution

- Skip tracing gRPC channels with OpenTelemetry OTLP exporter user
agents
- Skip tracing HTTP requests from OpenTelemetry OTLP exporters  
- Added detection logic for both gRPC metadata and HTTP headers

## Testing

Added tests verifying that OpenTelemetry exporters don't generate spans
when `DD_LOGS_OTEL_ENABLED` is enabled.

## Risks

Low - only affects OpenTelemetry integration when enabled.

Co-authored-by: Munir Abdinur <[email protected]>

Author: dd-octo-sts[bot]

ddtrace/contrib/internal/grpc/client_interceptor.py

@@ -13,6 +13,7 @@
 from ddtrace.contrib import trace_utils
 from ddtrace.contrib.internal.grpc import constants
 from ddtrace.contrib.internal.grpc import utils
+from ddtrace.contrib.internal.grpc.utils import is_otlp_export
 from ddtrace.ext import SpanKind
 from ddtrace.ext import SpanTypes
 from ddtrace.internal import core
@@ -193,6 +194,13 @@ def __init__(self, pin, host, port):
         self._port = port
 
     def _intercept_client_call(self, method_kind, client_call_details):
+        metadata = []
+        if client_call_details.metadata is not None:
+            metadata = list(client_call_details.metadata)
+
+        if is_otlp_export(metadata):
+            return None, client_call_details
+
         tracer: Tracer = self._pin.tracer
 
         # Instead of using .trace, create the span and activate it at points where we call the continuations
@@ -228,9 +236,6 @@ def _intercept_client_call(self, method_kind, client_call_details):
             # NOTE: We need to pass the span to the HTTPPropagator since it isn't active at this point
             HTTPPropagator.inject(span.context, headers, span)
 
-        metadata = []
-        if client_call_details.metadata is not None:
-            metadata = list(client_call_details.metadata)
         metadata.extend(headers.items())
 
         client_call_details = _ClientCallDetails(
@@ -247,6 +252,8 @@ def intercept_unary_unary(self, continuation, client_call_details, request):
             constants.GRPC_METHOD_KIND_UNARY,
             client_call_details,
         )
+        if span is None:
+            return continuation(client_call_details, request)
         with _activated_span(self._pin.tracer, span):
             try:
                 response = continuation(client_call_details, request)
@@ -265,6 +272,8 @@ def intercept_unary_stream(self, continuation, client_call_details, request):
             constants.GRPC_METHOD_KIND_SERVER_STREAMING,
             client_call_details,
         )
+        if span is None:
+            return continuation(client_call_details, request)
         with _activated_span(self._pin.tracer, span):
             response_iterator = continuation(client_call_details, request)
             response_iterator = _WrappedResponseCallFuture(response_iterator, span, self._pin.tracer)
@@ -275,6 +284,8 @@ def intercept_stream_unary(self, continuation, client_call_details, request_iter
             constants.GRPC_METHOD_KIND_CLIENT_STREAMING,
             client_call_details,
         )
+        if span is None:
+            return continuation(client_call_details, request_iterator)
         with _activated_span(self._pin.tracer, span):
             try:
                 response = continuation(client_call_details, request_iterator)
@@ -293,6 +304,8 @@ def intercept_stream_stream(self, continuation, client_call_details, request_ite
             constants.GRPC_METHOD_KIND_BIDI_STREAMING,
             client_call_details,
         )
+        if span is None:
+            return continuation(client_call_details, request_iterator)
         with _activated_span(self._pin.tracer, span):
             response_iterator = continuation(client_call_details, request_iterator)
             response_iterator = _WrappedResponseCallFuture(response_iterator, span, self._pin.tracer)

ddtrace/contrib/internal/grpc/constants.py

@@ -24,3 +24,4 @@
 GRPC_AIO_SERVICE_SERVER = "grpc-aio-server"
 GRPC_SERVICE_CLIENT = "grpc-client"
 GRPC_AIO_SERVICE_CLIENT = "grpc-aio-client"
+USER_AGENT_HEADER = "user-agent"

ddtrace/contrib/internal/grpc/utils.py

@@ -1,10 +1,14 @@
 import ipaddress
 import logging
 import re
+from typing import Tuple
 from urllib import parse
 
+from ddtrace import config
 from ddtrace.contrib.internal.grpc import constants
+from ddtrace.contrib.internal.grpc.constants import USER_AGENT_HEADER
 from ddtrace.ext import net
+from ddtrace.internal.opentelemetry.constants import OTLP_EXPORTER_HEADER_IDENTIFIER
 
 
 log = logging.getLogger(__name__)
@@ -108,3 +112,18 @@ def _parse_rpc_repr_string(rpc_string, module):
 
     # Return the status code and details
     return code, details
+
+
+def is_otlp_export(metadata: Tuple) -> bool:
+    """
+    Determine if a gRPC channel is submitting data to the OpenTelemetry OTLP exporter.
+    """
+    if not (config._otel_logs_enabled or config._otel_metrics_enabled):
+        return False
+
+    for key, value in metadata:
+        if key == USER_AGENT_HEADER:
+            normalized_value = value.lower().replace(" ", "-")
+            if OTLP_EXPORTER_HEADER_IDENTIFIER in normalized_value:
+                return True
+    return False

ddtrace/contrib/internal/requests/connection.py

@@ -3,17 +3,21 @@
 from typing import Optional  # noqa:F401
 from urllib import parse
 
+import requests
+
 import ddtrace
 from ddtrace import config
 from ddtrace._trace.pin import Pin
 from ddtrace.constants import _SPAN_MEASURED_KEY
 from ddtrace.constants import SPAN_KIND
 from ddtrace.contrib import trace_utils
+from ddtrace.contrib.internal.requests.constants import USER_AGENT_HEADER
 from ddtrace.contrib.internal.trace_utils import _sanitized_url
 from ddtrace.ext import SpanKind
 from ddtrace.ext import SpanTypes
 from ddtrace.internal.constants import COMPONENT
 from ddtrace.internal.logger import get_logger
+from ddtrace.internal.opentelemetry.constants import OTLP_EXPORTER_HEADER_IDENTIFIER
 from ddtrace.internal.schema import schematize_url_operation
 from ddtrace.internal.schema.span_attribute_schema import SpanDirection
 from ddtrace.internal.utils import get_argument_value
@@ -24,6 +28,17 @@
 log = get_logger(__name__)
 
 
+def is_otlp_export(request: requests.models.Request) -> bool:
+    """Determine if a request is submitting data to the OpenTelemetry OTLP exporter."""
+    if not (config._otel_logs_enabled or config._otel_metrics_enabled):
+        return False
+    user_agent = request.headers.get(USER_AGENT_HEADER, "")
+    normalized_user_agent = user_agent.lower().replace(" ", "-")
+    if OTLP_EXPORTER_HEADER_IDENTIFIER in normalized_user_agent:
+        return True
+    return False
+
+
 def _extract_hostname_and_path(uri):
     # type: (str) -> str
     parsed_uri = parse.urlparse(uri)
@@ -67,7 +82,7 @@ def _wrap_send(func, instance, args, kwargs):
         return func(*args, **kwargs)
 
     request = get_argument_value(args, kwargs, 0, "request")
-    if not request:
+    if not request or is_otlp_export(request):
         return func(*args, **kwargs)
 
     url = _sanitized_url(request.url)

ddtrace/contrib/internal/requests/constants.py

@@ -1 +1,2 @@
 DEFAULT_SERVICE = "requests"
+USER_AGENT_HEADER = "User-Agent"

ddtrace/internal/opentelemetry/constants.py

@@ -0,0 +1 @@
+OTLP_EXPORTER_HEADER_IDENTIFIER = "otel-otlp-exporter-python"

releasenotes/notes/otel-traced-export-445b99748c059bea.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    otel: Prevents OpenTelemetry OTLP exporter connections from being traced by ddtrace. 
+    ddtrace internal connections (gRPC and HTTP) are now excluded from tracing to prevent circular instrumentation.

tests/opentelemetry/test_logs.py

@@ -504,3 +504,62 @@ def test_otel_trace_log_correlation():
     assert (
         int(attributes["span_id"], 16) == span_context.span_id
     ), f"Expected span_id_hex to be set to {attributes['span_id']} but found: {span_context.span_id}"
+
+
+@pytest.mark.skipif(
+    EXPORTER_VERSION < MINIMUM_SUPPORTED_VERSION,
+    reason=f"OpenTelemetry exporter version {MINIMUM_SUPPORTED_VERSION} is required to export logs",
+)
+@pytest.mark.snapshot()
+@pytest.mark.subprocess(ddtrace_run=True, env={"DD_LOGS_OTEL_ENABLED": "true"})
+def test_otel_logs_does_not_generate_client_grpc_spans():
+    """
+    Test that OpenTelemetry grpc logs exporter does not generate client grpc spans.
+    """
+    from logging import getLogger
+
+    from opentelemetry._logs import get_logger_provider
+
+    from tests.opentelemetry.test_logs import create_mock_grpc_server
+
+    logger = getLogger()
+    mock_service, server = create_mock_grpc_server()
+
+    try:
+        server.start()
+        logger.error("test_otel_logs_grpc")
+        get_logger_provider().force_flush()
+    finally:
+        server.stop(0)
+
+    assert mock_service.received_requests, "Expected gRPC log export requests but received none"
+
+
+@pytest.mark.skipif(
+    EXPORTER_VERSION < MINIMUM_SUPPORTED_VERSION,
+    reason=f"OpenTelemetry exporter version {MINIMUM_SUPPORTED_VERSION} is required to export logs",
+)
+@pytest.mark.snapshot()
+@pytest.mark.subprocess(
+    ddtrace_run=True, env={"DD_LOGS_OTEL_ENABLED": "true", "OTEL_EXPORTER_OTLP_PROTOCOL": "http/protobuf"}
+)
+def test_otel_logs_does_not_generate_client_http_spans():
+    """Test that OpenTelemetry http logs exporter does not generate client spans."""
+    from logging import getLogger
+    from unittest.mock import Mock
+    from unittest.mock import patch
+
+    from opentelemetry._logs import get_logger_provider
+
+    logger = getLogger()
+    with patch("requests.sessions.Session.request") as mock_request:
+        mock_request.return_value = Mock(status_code=200)
+
+        logger.error("test_otel_logs_http")
+        get_logger_provider().force_flush()
+
+        log_request_found = any(
+            len(call[0]) >= 2 and call[0][0] == "POST" and "/v1/logs" in call[0][1]
+            for call in mock_request.call_args_list
+        )
+        assert log_request_found, f"Expected HTTP log export request but found none: {mock_request.call_args_list}"

tests/snapshots/tests.opentelemetry.test_logs.test_otel_logs_does_not_generate_client_grpc_spans.json

@@ -0,0 +1,35 @@
+[[
+  {
+    "name": "grpc",
+    "service": "grpc-server",
+    "resource": "/opentelemetry.proto.collector.logs.v1.LogsService/Export",
+    "trace_id": 0,
+    "span_id": 1,
+    "parent_id": 0,
+    "type": "grpc",
+    "error": 0,
+    "meta": {
+      "_dd.base_service": "ddtrace_subprocess_dir",
+      "_dd.p.dm": "-0",
+      "_dd.p.tid": "68f8d7df00000000",
+      "component": "grpc_server",
+      "grpc.method.kind": "unary",
+      "grpc.method.name": "Export",
+      "grpc.method.package": "opentelemetry.proto.collector.logs.v1",
+      "grpc.method.path": "/opentelemetry.proto.collector.logs.v1.LogsService/Export",
+      "grpc.method.service": "LogsService",
+      "language": "python",
+      "rpc.service": "opentelemetry.proto.collector.logs.v1.LogsService",
+      "runtime-id": "f889b527dbdc40afa921bb54a08f8c90",
+      "span.kind": "server"
+    },
+    "metrics": {
+      "_dd.measured": 1,
+      "_dd.top_level": 1,
+      "_dd.tracer_kr": 1.0,
+      "_sampling_priority_v1": 1,
+      "process_id": 32526
+    },
+    "duration": 31000,
+    "start": 1761138655401326000
+  }]]