improv: add log filter in root handler to prevent child log records duplication

Author: heitorlessa

aws_lambda_powertools/logging/filters.py

@@ -0,0 +1,12 @@
+import logging
+
+
+class SuppressFilter(logging.Filter):
+    def __init__(self, logger):
+        self.logger = logger
+
+    def filter(self, record):  # noqa: A003
+        """Suppress Log Records from registered logger"""
+        if self.logger in record.name:
+            return False
+        return True

aws_lambda_powertools/logging/logger.py

@@ -8,6 +8,7 @@
 from typing import Any, Callable, Dict, Union
 
 from .exceptions import InvalidLoggerSamplingRateError
+from .filters import SuppressFilter
 from .formatter import JsonFormatter
 from .lambda_context import build_lambda_context_model
 
@@ -147,13 +148,6 @@ def _get_logger(self):
     def _init_logger(self, **kwargs):
         """Configures new logger"""
 
-        # Lambda by default configures the root logger handler
-        # therefore, we need to remove it to prevent messages being logged twice
-        # when customers use our Logger
-        logger.debug("Removing Lambda root handler whether it exists")
-        root_logger = logging.getLogger()
-        root_logger.handlers.clear()
-
         # Skip configuration if it's a child logger to prevent
         # multiple handlers being attached as well as different sampling mechanisms
         # and multiple messages from being logged as handlers can be duplicated
@@ -163,6 +157,10 @@ def _init_logger(self, **kwargs):
             self._logger.addHandler(self._handler)
             self.structure_logs(**kwargs)
 
+            logger.debug("Adding filter in root logger to suppress child logger records to bubble up")
+            for handler in logging.root.handlers:
+                handler.addFilter(SuppressFilter(self.service))
+
     def _configure_sampling(self):
         """Dynamically set log level based on sampling rate