fix: remove dependency on api-core for logging (#1748)

* fix: remove dep on api-core for logging

* disable propagation to the root logger

* update async helpers tests

* fix lint issue

Author: ohmayr

google/auth/_helpers.py

@@ -27,16 +27,14 @@
 
 from google.auth import exceptions
 
-try:
-    # TODO(https://github.com/googleapis/python-api-core/issues/813): Remove `# type: ignore` when
-    # `google-api-core` type hints issue is resolved.
-    from google.api_core import client_logging  # type: ignore # noqa: F401
 
-    CLIENT_LOGGING_SUPPORTED = True  # pragma: NO COVER
-# TODO(https://github.com/googleapis/google-auth-library-python/issues/1690): Remove `pragma: NO COVER` once
-# logging is supported in minimum version of google-api-core.
-except ImportError:  # pragma: NO COVER
-    CLIENT_LOGGING_SUPPORTED = False
+# _BASE_LOGGER_NAME is the base logger for all google-based loggers.
+_BASE_LOGGER_NAME = "google"
+
+# _LOGGING_INITIALIZED ensures that base logger is only configured once
+# (unless already configured by the end-user).
+_LOGGING_INITIALIZED = False
+
 
 # The smallest MDS cache used by this library stores tokens until 4 minutes from
 # expiry.
@@ -344,6 +342,20 @@ def _hash_value(value, field_name: str) -> Optional[str]:
     return f"hashed_{field_name}-{hex_digest}"
 
 
+def _logger_configured(logger: logging.Logger) -> bool:
+    """Determines whether `logger` has non-default configuration
+
+    Args:
+      logger: The logger to check.
+
+    Returns:
+      bool: Whether the logger has any non-default configuration.
+    """
+    return (
+        logger.handlers != [] or logger.level != logging.NOTSET or not logger.propagate
+    )
+
+
 def is_logging_enabled(logger: logging.Logger) -> bool:
     """
     Checks if debug logging is enabled for the given logger.
@@ -354,7 +366,23 @@ def is_logging_enabled(logger: logging.Logger) -> bool:
     Returns:
         True if debug logging is enabled, False otherwise.
     """
-    return CLIENT_LOGGING_SUPPORTED and logger.isEnabledFor(logging.DEBUG)
+    # NOTE: Log propagation to the root logger is disabled unless
+    # the base logger i.e. logging.getLogger("google") is
+    # explicitly configured by the end user. Ideally this
+    # needs to happen in the client layer (already does for GAPICs).
+    # However, this is implemented here to avoid logging
+    # (if a root logger is configured) when a version of google-auth
+    # which supports logging is used with:
+    #  - an older version of a GAPIC which does not support logging.
+    #  - Apiary client which does not support logging.
+    global _LOGGING_INITIALIZED
+    if not _LOGGING_INITIALIZED:
+        base_logger = logging.getLogger(_BASE_LOGGER_NAME)
+        if not _logger_configured(base_logger):
+            base_logger.propagate = False
+        _LOGGING_INITIALIZED = True
+
+    return logger.isEnabledFor(logging.DEBUG)
 
 
 def request_log(

tests/aio/test__helpers.py

@@ -14,48 +14,64 @@
 
 import json
 import logging
-from unittest import mock
 
 import pytest  # type: ignore
 
 from google.auth.aio import _helpers
 
+# _MOCK_BASE_LOGGER_NAME is the base logger namespace used for testing.
+_MOCK_BASE_LOGGER_NAME = "foogle"
+
+# _MOCK_CHILD_LOGGER_NAME is the child logger namespace used for testing.
+_MOCK_CHILD_LOGGER_NAME = "foogle.bar"
+
 
 @pytest.fixture
 def logger():
-    """Provides a basic logger instance for testing."""
-    return logging.getLogger(__name__)
+    """Returns a child logger for testing."""
+    logger = logging.getLogger(_MOCK_CHILD_LOGGER_NAME)
+    logger.level = logging.NOTSET
+    logger.handlers = []
+    logger.propagate = True
+    return logger
+
+
+@pytest.fixture
+def base_logger():
+    """Returns a child logger for testing."""
+    logger = logging.getLogger(_MOCK_BASE_LOGGER_NAME)
+    logger.level = logging.NOTSET
+    logger.handlers = []
+    logger.propagate = True
+    return logger
 
 
 @pytest.mark.asyncio
-async def test_response_log_debug_enabled(logger, caplog):
-    logger.setLevel(logging.DEBUG)
-    with mock.patch("google.auth._helpers.CLIENT_LOGGING_SUPPORTED", True):
-        await _helpers.response_log_async(logger, {"payload": None})
+async def test_response_log_debug_enabled(logger, caplog, base_logger):
+    caplog.set_level(logging.DEBUG, logger=_MOCK_CHILD_LOGGER_NAME)
+    await _helpers.response_log_async(logger, {"payload": None})
     assert len(caplog.records) == 1
     record = caplog.records[0]
     assert record.message == "Response received..."
     assert record.httpResponse == "<class 'NoneType'>"
 
 
 @pytest.mark.asyncio
-async def test_response_log_debug_disabled(logger, caplog):
-    logger.setLevel(logging.INFO)
-    with mock.patch("google.auth._helpers.CLIENT_LOGGING_SUPPORTED", True):
-        await _helpers.response_log_async(logger, "another_response")
+async def test_response_log_debug_disabled(logger, caplog, base_logger):
+    caplog.set_level(logging.INFO, logger=_MOCK_CHILD_LOGGER_NAME)
+    await _helpers.response_log_async(logger, "another_response")
     assert "Response received..." not in caplog.text
 
 
 @pytest.mark.asyncio
-async def test_response_log_debug_enabled_response_json(logger, caplog):
+async def test_response_log_debug_enabled_response_json(logger, caplog, base_logger):
     class MockResponse:
         async def json(self):
             return {"key1": "value1", "key2": "value2", "key3": "value3"}
 
     response = MockResponse()
-    logger.setLevel(logging.DEBUG)
-    with mock.patch("google.auth._helpers.CLIENT_LOGGING_SUPPORTED", True):
-        await _helpers.response_log_async(logger, response)
+    caplog.set_level(logging.DEBUG, logger=_MOCK_CHILD_LOGGER_NAME)
+    await _helpers.response_log_async(logger, response)
     assert len(caplog.records) == 1
     record = caplog.records[0]
     assert record.message == "Response received..."