1# Copyright 2019 The gRPC Authors 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14"""Tests for an actual dns resolution.""" 15 16import logging 17import unittest 18 19import grpc 20 21from tests.unit import test_common 22from tests.unit.framework.common import test_constants 23 24_METHOD = "/ANY/METHOD" 25_REQUEST = b"\x00\x00\x00" 26_RESPONSE = _REQUEST 27 28 29class GenericHandler(grpc.GenericRpcHandler): 30 def service(self, unused_handler_details): 31 return grpc.unary_unary_rpc_method_handler( 32 lambda request, unused_context: request, 33 ) 34 35 36class DNSResolverTest(unittest.TestCase): 37 def setUp(self): 38 self._server = test_common.test_server() 39 self._server.add_generic_rpc_handlers((GenericHandler(),)) 40 self._port = self._server.add_insecure_port("[::]:0") 41 self._server.start() 42 43 def tearDown(self): 44 self._server.stop(None) 45 46 def test_connect_loopback(self): 47 # NOTE(https://github.com/grpc/grpc/issues/18422) 48 # In short, Gevent + C-Ares = Segfault. The C-Ares driver is not 49 # supported by custom io manager like "gevent" 50 # NOTE(b/201064791): use loopback46.unittest.grpc.io since 51 # it returns the expected responses even when DNS64 dns servers 52 # are used on the test worker (and for purposes of this 53 # test the use of loopback4 vs loopback46 makes no difference). 54 with grpc.insecure_channel( 55 "loopback46.unittest.grpc.io:%d" % self._port 56 ) as channel: 57 self.assertEqual( 58 channel.unary_unary( 59 _METHOD, 60 _registered_method=True, 61 )( 62 _REQUEST, 63 timeout=10, 64 ), 65 _RESPONSE, 66 ) 67 68 69if __name__ == "__main__": 70 logging.basicConfig() 71 unittest.main(verbosity=2) 72