fix(otlp): allow multiple signals [backport 3.17] (#15128)

Backport 06e349b from #15107 to 3.17.

## Description

Fixed a circular import issue when enabling both OpenTelemetry metrics
and logs simultaneously (`DD_METRICS_OTEL_ENABLED=true` +
`DD_LOGS_OTEL_ENABLED=true`). Update lazy initialization to enable full
opentelemetry support when `opentelemetry` is first imported.

## Testing

Verified that enabling multiple OpenTelemetry signals together no longer
produces circular import errors. Confirmed individual signals
(metrics-only, logs-only, traces-only) still work correctly.

## Risks

Low risk. Changes initialization timing from lazy to eager, but no
functional behavior changes for users.

## Additional Notes

Enables proper multi-signal OpenTelemetry support for comprehensive
observability (traces + metrics + logs).

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

Author: dd-octo-sts[bot]

ddtrace/bootstrap/preload.py

@@ -64,36 +64,27 @@ def register_post_preload(func: t.Callable) -> None:
 if config._runtime_metrics_enabled:
     RuntimeWorker.enable()
 
-if config._otel_trace_enabled:
 
-    @ModuleWatchdog.after_module_imported("opentelemetry.trace")
-    def _ot_traces(_):
+@ModuleWatchdog.after_module_imported("opentelemetry")
+def _otel_signals(_):
+    if config._otel_trace_enabled:
         from opentelemetry.trace import set_tracer_provider
 
         from ddtrace.opentelemetry import TracerProvider
 
         set_tracer_provider(TracerProvider())
 
+    if config._otel_logs_enabled:
+        from ddtrace.internal.opentelemetry.logs import set_otel_logs_provider
 
-if config._otel_metrics_enabled:
+        set_otel_logs_provider()
 
-    @ModuleWatchdog.after_module_imported("opentelemetry.metrics")
-    def _otel_metrics(_):
+    if config._otel_metrics_enabled:
         from ddtrace.internal.opentelemetry.metrics import set_otel_meter_provider
 
         set_otel_meter_provider()
 
 
-if config._otel_logs_enabled:
-
-    @register_post_preload
-    def _otel_logs():
-        # Post load to ensure that the logger provider is not overridden by module unloading
-        from ddtrace.internal.opentelemetry.logs import set_otel_logs_provider
-
-        set_otel_logs_provider()
-
-
 if config._llmobs_enabled:
     from ddtrace.llmobs import LLMObs
 

ddtrace/opentelemetry/__init__.py

@@ -9,6 +9,9 @@
 All operations defined the opentelemetry trace api are configured to use the ddtrace global tracer (``ddtrace.tracer``)
 and generate datadog compatible traces. By default all opentelemetry traces are submitted to a Datadog agent.
 
+**Note:** OpenTelemetry support is lazily loaded when the ``opentelemetry`` package is first imported. Ensure
+``import opentelemetry...`` or ``from opentelemetry....`` is present in your code.
+
 
 Configuration
 -------------

releasenotes/notes/fix-otel-multiple-signals-254a3a0abcc364f3.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    opentelemetry: Fixed circular import when enabling multiple OpenTelemetry signals (metrics + logs) simultaneously. 

tests/opentelemetry/test_context.py

@@ -11,6 +11,9 @@
 import ddtrace
 from ddtrace.constants import MANUAL_DROP_KEY
 from ddtrace.constants import MANUAL_KEEP_KEY
+from ddtrace.internal.opentelemetry.logs import MINIMUM_SUPPORTED_VERSION
+
+from .test_logs import EXPORTER_VERSION
 
 
 @pytest.mark.snapshot(wait_for_num_traces=1)
@@ -204,3 +207,25 @@ def test_otel_baggage_removal_propagation_to_ddtrace(oteltracer):
             assert ddspan.context.get_baggage_item("key4") == "value4"
             assert ddspan.context.get_baggage_item("key1") is None
             assert ddspan.context.get_baggage_item("key2") is None
+
+
+@pytest.mark.skipif(
+    EXPORTER_VERSION < MINIMUM_SUPPORTED_VERSION,
+    reason=f"OpenTelemetry exporter version {MINIMUM_SUPPORTED_VERSION} is required to export logs",
+)
+@pytest.mark.subprocess(
+    env={"DD_TRACE_OTEL_ENABLED": "true", "DD_LOGS_OTEL_ENABLED": "true", "DD_METRICS_OTEL_ENABLED": "true"},
+    ddtrace_run=True,
+)
+def test_providers_are_set():
+    from opentelemetry._logs import get_logger_provider
+    from opentelemetry.metrics import get_meter_provider
+    from opentelemetry.trace import get_tracer_provider
+
+    tracer_provider = get_tracer_provider()
+    meter_provider = get_meter_provider()
+    logger_provider = get_logger_provider()
+
+    assert tracer_provider.get_tracer(__name__) is not None
+    assert meter_provider.get_meter(__name__) is not None
+    assert logger_provider.get_logger(__name__) is not None

tests/opentelemetry/test_logs.py

@@ -90,7 +90,7 @@ def test_otel_api_version_not_supported(ddtrace_run_python_code_in_subprocess):
     """Test error when OpenTelemetry API version is too old."""
     env = os.environ.copy()
     env["DD_LOGS_OTEL_ENABLED"] = "true"
-    stdout, stderr, status, _ = ddtrace_run_python_code_in_subprocess(code="", env=env)
+    stdout, stderr, status, _ = ddtrace_run_python_code_in_subprocess(code="import opentelemetry", env=env)
     assert status == 0, (stdout, stderr)
     assert (
         "OpenTelemetry API requires version 1.15.0 or higher to enable logs collection. "
@@ -107,7 +107,7 @@ def test_otel_sdk_not_installed(ddtrace_run_python_code_in_subprocess):
     """Test error when OpenTelemetry SDK is not installed."""
     env = os.environ.copy()
     env["DD_LOGS_OTEL_ENABLED"] = "true"
-    stdout, stderr, status, _ = ddtrace_run_python_code_in_subprocess(code="", env=env)
+    stdout, stderr, status, _ = ddtrace_run_python_code_in_subprocess(code="import opentelemetry", env=env)
     assert status == 0, (stdout, stderr)
 
     assert (

tests/telemetry/test_writer.py

@@ -83,6 +83,7 @@ def test_app_started_event_configuration_override(test_agent_session, run_python
 import ddtrace.settings.symbol_db
 import ddtrace.settings.dynamic_instrumentation
 import ddtrace.settings.exception_replay
+import opentelemetry
     """
 
     env = os.environ.copy()