Monkeypatch basicConfig

Author: pmcollins

opentelemetry-sdk/src/opentelemetry/sdk/_configuration/__init__.py

@@ -253,6 +253,37 @@ def _init_logging(
     set_event_logger_provider(event_logger_provider)
 
     if setup_logging_handler:
+        # noinspection PyPep8Naming
+        original_basicConfig = logging.basicConfig
+
+        # noinspection PyPep8Naming
+        def patched_basicConfig(*args, **kwargs):
+            # Get the root logger
+            root = logging.getLogger()
+
+            # Check if the only handler is our OTel handler
+            has_only_otel = len(root.handlers) == 1 and isinstance(
+                root.handlers[0], LoggingHandler
+            )
+
+            if has_only_otel:
+                # Temporarily remove OTel handler
+                otel_handler = root.handlers[0]
+                root.handlers = []
+
+                # Call original basicConfig
+                original_basicConfig(*args, **kwargs)
+
+                # Add OTel handler back
+                root.addHandler(otel_handler)
+            else:
+                # Normal behavior
+                original_basicConfig(*args, **kwargs)
+
+        # Apply the monkey patch
+        logging.basicConfig = patched_basicConfig
+
+        # Add OTel handler
         handler = LoggingHandler(
             level=logging.NOTSET, logger_provider=provider
         )

opentelemetry-sdk/tests/test_configurator.py

@@ -842,6 +842,32 @@ def test_initialize_components_kwargs(
             True,
         )
 
+    def test_basicConfig_works_with_otel_handler(self):
+        with ClearLoggingHandlers():
+            # Initialize auto-instrumentation with logging enabled
+            _init_logging(
+                {"otlp": DummyOTLPLogExporter},
+                Resource.create({}),
+                setup_logging_handler=True,
+            )
+
+            # Call basicConfig - this should work despite OTel handler being present
+            logging.basicConfig(level=logging.INFO)
+
+            # Verify a StreamHandler was added
+            root_logger = logging.getLogger()
+            stream_handlers = [
+                h
+                for h in root_logger.handlers
+                if isinstance(h, logging.StreamHandler)
+                and not isinstance(h, LoggingHandler)
+            ]
+            self.assertEqual(
+                len(stream_handlers),
+                1,
+                "basicConfig should add a StreamHandler even when OTel handler exists",
+            )
+
 
 class TestMetricsInit(TestCase):
     def setUp(self):