fix: send StructuredLogHandler instrumentation log using an explicit logger (#705)

Author: daniel-sanche

google/cloud/logging_v2/handlers/structured_log.py

@@ -131,4 +131,8 @@ def emit(self, record):
     def emit_instrumentation_info(self):
         google.cloud.logging_v2._instrumentation_emitted = True
         diagnostic_object = _create_diagnostic_entry()
-        logging.info(diagnostic_object.payload)
+        struct_logger = logging.getLogger(__name__)
+        struct_logger.addHandler(self)
+        struct_logger.setLevel(logging.INFO)
+        struct_logger.info(diagnostic_object.payload)
+        struct_logger.handlers.clear()

tests/unit/handlers/test_structured_log.py

@@ -624,7 +624,8 @@ def test_valid_instrumentation_info(self):
         import mock
         import json
 
-        with mock.patch.object(logging, "info") as mock_log:
+        logger = logging.getLogger("google.cloud.logging_v2.handlers.structured_log")
+        with mock.patch.object(logger, "info") as mock_log:
             handler = self._make_one()
             handler.emit_instrumentation_info()
             mock_log.assert_called_once()