Fix exception thrown when LoggerProvider not configured (open-telemetry#3423)

Author: lzchen

CHANGELOG.md

@@ -7,12 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- Fix error when no LoggerProvider configured for LoggingHandler
+  ([#3423](https://github.com/open-telemetry/opentelemetry-python/pull/3423))
+  
 ## Version 1.20.0/0.41b0 (2023-09-04)
 
 - Modify Prometheus exporter to translate non-monotonic Sums into Gauges
   ([#3306](https://github.com/open-telemetry/opentelemetry-python/pull/3306))
 
-
 ## Version 1.19.0/0.40b0 (2023-07-13)
 
 - Drop `setuptools` runtime requirement.

opentelemetry-sdk/src/opentelemetry/sdk/_logs/_internal/__init__.py

@@ -27,6 +27,7 @@
 from opentelemetry._logs import LoggerProvider as APILoggerProvider
 from opentelemetry._logs import LogRecord as APILogRecord
 from opentelemetry._logs import (
+    NoOpLogger,
     SeverityNumber,
     get_logger,
     get_logger_provider,
@@ -532,11 +533,12 @@ def _translate(self, record: logging.LogRecord) -> LogRecord:
 
     def emit(self, record: logging.LogRecord) -> None:
         """
-        Emit a record.
+        Emit a record. Skip emitting if logger is NoOp.
 
         The record is translated to OTel format, and then sent across the pipeline.
         """
-        self._logger.emit(self._translate(record))
+        if not isinstance(self._logger, NoOpLogger):
+            self._logger.emit(self._translate(record))
 
     def flush(self) -> None:
         """

opentelemetry-sdk/tests/logs/test_handler.py

@@ -15,7 +15,7 @@
 import unittest
 from unittest.mock import Mock
 
-from opentelemetry._logs import SeverityNumber
+from opentelemetry._logs import NoOpLoggerProvider, SeverityNumber
 from opentelemetry._logs import get_logger as APIGetLogger
 from opentelemetry.attributes import BoundedAttributes
 from opentelemetry.sdk import trace
@@ -64,6 +64,21 @@ def test_handler_custom_log_level(self):
             logger.critical("No Time For Caution")
         self.assertEqual(emitter_mock.emit.call_count, 2)
 
+    # pylint: disable=protected-access
+    def test_log_record_emit_noop(self):
+        noop_logger_provder = NoOpLoggerProvider()
+        logger_mock = APIGetLogger(
+            __name__, logger_provider=noop_logger_provder
+        )
+        logger = logging.getLogger(__name__)
+        handler_mock = Mock(spec=LoggingHandler)
+        handler_mock._logger = logger_mock
+        handler_mock.level = logging.WARNING
+        logger.addHandler(handler_mock)
+        with self.assertLogs(level=logging.WARNING):
+            logger.warning("Warning message")
+        handler_mock._translate.assert_not_called()
+
     def test_log_record_no_span_context(self):
         emitter_provider_mock = Mock(spec=LoggerProvider)
         emitter_mock = APIGetLogger(