fix(emissions_tracker): warn and skip LOGGER output when logging_logger is missing (#1412)

codecarbon/emissions_tracker.py

@@ -639,7 +639,15 @@ def _init_output_methods(self, *, api_key: str = None):
             )
 
         if OutputMethod.LOGGER in methods:
-            self._output_handlers.append(self._logging_logger)
+            if self._logging_logger is None:
+                logger.warning(
+                    "OutputMethod.LOGGER was requested but no `logging_logger`"
+                    " was provided, so the logger output is skipped. Pass"
+                    " `logging_logger=LoggerOutput(...)` to EmissionsTracker"
+                    " to enable it."
+                )
+            else:
+                self._output_handlers.append(self._logging_logger)
 
         if self._emissions_endpoint:
             self._output_handlers.append(HTTPOutput(self._emissions_endpoint))

tests/test_emissions_tracker.py

@@ -1,3 +1,4 @@
+import logging
 import os
 import shutil
 import sys
@@ -20,6 +21,7 @@
 )
 from codecarbon.external.geography import CloudMetadata
 from codecarbon.output import BoAmpsOutput, CodeCarbonAPIOutput, OutputMethod
+from codecarbon.output_methods.logger import LoggerOutput
 from tests.fake_modules import pynvml as fake_pynvml
 from tests.testdata import (
     GEO_METADATA_CANADA,
@@ -1099,6 +1101,45 @@ def test_scheduler_warning_shown_when_running(
                 scheduler_warning_found, "Expected scheduler warning was not found"
             )
 
+    @mock.patch("codecarbon.emissions_tracker.logger")
+    def test_logger_output_warns_and_skips_without_logging_logger(
+        self,
+        mock_logger,
+        mock_cli_setup,
+        mock_log_values,
+        mocked_get_gpu_details,
+        mocked_env_cloud_details,
+        mocked_get_gpu_utilization_list,
+        mocked_is_gpu_details_available,
+        mocked_is_nvidia_system,
+    ):
+        tracker = EmissionsTracker(
+            project_name=self.project_name,
+            output_methods=["logger"],
+        )
+
+        self.assertNotIn(None, tracker._output_handlers)
+        warnings = [str(c.args[0]) for c in mock_logger.warning.call_args_list]
+        self.assertTrue(any("logging_logger" in w for w in warnings))
+
+    def test_logger_output_succeeds_with_logging_logger(
+        self,
+        mock_cli_setup,
+        mock_log_values,
+        mocked_get_gpu_details,
+        mocked_env_cloud_details,
+        mocked_get_gpu_utilization_list,
+        mocked_is_gpu_details_available,
+        mocked_is_nvidia_system,
+    ):
+        my_logger = logging.getLogger("test_logger_output")
+        tracker = EmissionsTracker(
+            project_name=self.project_name,
+            output_methods=["logger"],
+            logging_logger=LoggerOutput(my_logger),
+        )
+        self.assertIsNotNone(tracker)
+
     def test_get_detected_hardware(
         self,
         mock_cli_setup,