Add NullHandler to avoid warnings about no handler

src/python/grpcio/grpc/_channel.py

@@ -25,6 +25,7 @@ from grpc._cython import cygrpc
 from grpc.framework.foundation import callable_util
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler)
 
 _USER_AGENT = 'grpc-python/{}'.format(_grpcio_metadata.__version__)
 

src/python/grpcio/grpc/_common.py

@@ -21,6 +21,7 @@ import grpc
 from grpc._cython import cygrpc
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler())
 
 CYGRPC_CONNECTIVITY_STATE_TO_CHANNEL_CONNECTIVITY = {
     cygrpc.ConnectivityState.idle:

src/python/grpcio/grpc/_cython/_cygrpc/grpc_string.pyx.pxi

@@ -15,6 +15,7 @@
 import logging
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler())
 
 # This function will ascii encode unicode string inputs if neccesary.
 # In Python3, unicode strings are the default str type.

src/python/grpcio/grpc/_cython/_cygrpc/server.pyx.pxi

@@ -19,6 +19,7 @@ import time
 import grpc
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler())
 
 cdef class Server:
 

src/python/grpcio/grpc/_plugin_wrapping.py

@@ -21,6 +21,7 @@ from grpc import _common
 from grpc._cython import cygrpc
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler())
 
 
 class _AuthMetadataContext(

src/python/grpcio/grpc/framework/foundation/callable_util.py

@@ -22,6 +22,7 @@ import logging
 import six
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler())
 
 
 class Outcome(six.with_metaclass(abc.ABCMeta)):

src/python/grpcio/grpc/framework/foundation/logging_pool.py

@@ -18,6 +18,7 @@ import logging
 from concurrent import futures
 
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(logging.NullHandler())
 
 
 def _wrap(behavior):

src/python/grpcio/grpc/framework/foundation/stream_util.py

@@ -20,6 +20,7 @@ from grpc.framework.foundation import stream
 
 _NO_VALUE = object()
 _LOGGER = logging.getLogger(__name__)
+_LOGGER.addHandler(NullHandler())
 
 
 class TransformingConsumer(stream.Consumer):

src/python/grpcio_tests/tests/unit/_logging_test.py

@@ -19,6 +19,7 @@ import grpc
 import logging
 
 class LoggingTest(unittest.TestCase):
+
   def test_logger_not_occupied(self):
     self.assertEqual(0, len(logging.getLogger().handlers))