Incorporate review comments

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

@@ -228,7 +228,7 @@ class MetadataFlagsTest(unittest.TestCase):
 
             # Start the server after the connections are waiting
             wg.wait()
-            server = test_common.test_server()
+            server = test_common.test_server(reuse_port=True)
             server.add_generic_rpc_handlers((_GenericHandler(
                 weakref.proxy(self)),))
             server.add_insecure_port(addr)

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

@@ -42,24 +42,26 @@ class ReconnectTest(unittest.TestCase):
             'UnaryUnary':
             grpc.unary_unary_rpc_method_handler(_handle_unary_unary)
         })
-        with bound_socket() as (_, port):
-            server = grpc.server(server_pool, (handler,))
-            server.add_insecure_port('[::]:{}'.format(port))
+        options=(('grpc.so_reuseport', 0),)
+        with bound_socket() as (host, port):
+            addr = '{}:{}'.format(host, port)
+            server = grpc.server(server_pool, (handler,), options=options)
+            server.add_insecure_port(addr)
             server.start()
-            channel = grpc.insecure_channel('localhost:%d' % port)
-            multi_callable = channel.unary_unary(_UNARY_UNARY)
-            self.assertEqual(_RESPONSE, multi_callable(_REQUEST))
-            server.stop(None)
-            # By default, the channel connectivity is checked every 5s
-            # GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS can be set to change
-            # this.
-            time.sleep(5.1)
-            server = grpc.server(server_pool, (handler,))
-            server.add_insecure_port('[::]:{}'.format(port))
-            server.start()
-            self.assertEqual(_RESPONSE, multi_callable(_REQUEST))
-            server.stop(None)
-            channel.close()
+        channel = grpc.insecure_channel(addr)
+        multi_callable = channel.unary_unary(_UNARY_UNARY)
+        self.assertEqual(_RESPONSE, multi_callable(_REQUEST))
+        server.stop(None)
+        # By default, the channel connectivity is checked every 5s
+        # GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS can be set to change
+        # this.
+        time.sleep(5.1)
+        server = grpc.server(server_pool, (handler,), options=options)
+        server.add_insecure_port(addr)
+        server.start()
+        self.assertEqual(_RESPONSE, multi_callable(_REQUEST))
+        server.stop(None)
+        channel.close()
 
 
 if __name__ == '__main__':

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

@@ -100,14 +100,14 @@ def test_secure_channel(target, channel_credentials, server_host_override):
     return channel
 
 
-def test_server(max_workers=10):
+def test_server(max_workers=10, reuse_port=False):
     """Creates an insecure grpc server.
 
      These servers have SO_REUSEPORT disabled to prevent cross-talk.
      """
     return grpc.server(
         futures.ThreadPoolExecutor(max_workers=max_workers),
-        options=(('grpc.so_reuseport', 0),))
+        options=(('grpc.so_reuseport', int(reuse_port)),))
 
 
 class WaitGroup(object):