fix: override botocore logging to a NullHandler (#1538)

samcli/cli/main.py

@@ -97,6 +97,8 @@ def cli(ctx):
     sam_cli_logger = logging.getLogger("samcli")
     sam_cli_formatter = logging.Formatter("%(message)s")
     lambda_builders_logger = logging.getLogger("aws_lambda_builders")
+    botocore_logger = logging.getLogger("botocore")
 
     SamCliLogger.configure_logger(sam_cli_logger, sam_cli_formatter, logging.INFO)
     SamCliLogger.configure_logger(lambda_builders_logger, sam_cli_formatter, logging.INFO)
+    SamCliLogger.configure_null_logger(botocore_logger)

samcli/lib/utils/sam_logging.py

@@ -28,3 +28,22 @@ def configure_logger(logger, formatter, level):
         logger.setLevel(level)
         logger.propagate = False
         logger.addHandler(log_stream_handler)
+
+    @staticmethod
+    def configure_null_logger(logger):
+        """
+        Configure a Logger with a NullHandler
+
+        Useful for libraries that do not follow: https://docs.python.org/3.6/howto/logging.html#configuring-logging-for-a-library
+
+        Parameters
+        ----------
+        logger logging.getLogger
+            Logger to configure
+
+        Returns
+        -------
+        None
+        """
+        logger.propagate = False
+        logger.addHandler(logging.NullHandler())

tests/unit/lib/utils/test_sam_logging.py

@@ -22,3 +22,13 @@ def test_configure_samcli_logger(self, logging_patch):
         logger_mock.addHandler.assert_called_once_with(stream_handler_mock)
         stream_handler_mock.setLevel.assert_called_once_with(2)
         stream_handler_mock.setFormatter.assert_called_once_with(formatter_mock)
+
+    @patch("samcli.lib.utils.sam_logging.logging")
+    def test_configure_samcli_logger(self, logging_patch):
+        logger_mock = Mock()
+
+        SamCliLogger.configure_null_logger(logger_mock)
+
+        self.assertFalse(logger_mock.propagate)
+
+        logger_mock.addHandler.assert_called_once_with(logging_patch.NullHandler())