Remove the C++ test dependency on dig and dnsutils

templates/test/cpp/naming/resolver_component_tests_defs.include

@@ -22,8 +22,10 @@ FLAGS_test_bin_path=$(echo "$1" | grep '\--test_bin_path=' | cut -d "=" -f 2)
 FLAGS_dns_server_bin_path=$(echo "$2" | grep '\--dns_server_bin_path=' | cut -d "=" -f 2)
 FLAGS_records_config_path=$(echo "$3" | grep '\--records_config_path=' | cut -d "=" -f 2)
 FLAGS_test_dns_server_port=$(echo "$4" | grep '\--test_dns_server_port=' | cut -d "=" -f 2)
+FLAGS_test_dns_resolver_bin_path=$(echo "$5" | grep '\--test_dns_resolver_bin_path=' | cut -d "=" -f 2)
+FLAGS_test_tcp_connect_bin_path=$(echo "$6" | grep '\--test_tcp_connect_bin_path=' | cut -d "=" -f 2)
 
-for cmd_arg in "$FLAGS_test_bin_path" "$FLAGS_dns_server_bin_path" "$FLAGS_records_config_path" "$FLAGS_test_dns_server_port"; do
+for cmd_arg in "$FLAGS_test_bin_path" "$FLAGS_dns_server_bin_path" "$FLAGS_records_config_path" "$FLAGS_test_dns_server_port" "$FLAGS_test_dns_resolver_bin_path" "$FLAGS_test_tcp_connect_bin_path"; do
   if [[ "$cmd_arg" == "" ]]; then
     echo "Missing a CMD arg" && exit 1
   fi
@@ -41,10 +43,10 @@ echo "Local DNS server started. PID: $DNS_SERVER_PID"
 # Health check local DNS server TCP and UDP ports
 for ((i=0;i<30;i++));
 do
-  echo "Retry health-check DNS query to local DNS server over tcp and udp"
+  echo "Retry health-check local DNS server by attempting a DNS query and TCP handshake"
   RETRY=0
-  dig A health-check-local-dns-server-is-alive.resolver-tests.grpctestingexp. @localhost -p "$FLAGS_test_dns_server_port" +tries=1 +timeout=1 | grep '123.123.123.123' || RETRY=1
-  dig A health-check-local-dns-server-is-alive.resolver-tests.grpctestingexp. @localhost -p "$FLAGS_test_dns_server_port" +tries=1 +timeout=1 +tcp | grep '123.123.123.123' || RETRY=1
+  $FLAGS_test_dns_resolver_bin_path -s 127.0.0.1 -p "$FLAGS_test_dns_server_port" -n health-check-local-dns-server-is-alive.resolver-tests.grpctestingexp. -t 1 | grep '123.123.123.123' || RETRY=1
+  $FLAGS_test_tcp_connect_bin_path -s 127.0.0.1 -p "$FLAGS_test_dns_server_port" -t 1 || RETRY=1
   if [[ "$RETRY" == 0 ]]; then
     break
   fi;

test/cpp/naming/BUILD

@@ -47,4 +47,19 @@ grpc_py_binary(
   ]
 )
 
+grpc_py_binary(
+  name = "test_dns_resolver",
+  srcs = ["test_dns_resolver.py"],
+  testonly = True,
+  external_deps = [
+      "twisted",
+  ]
+)
+
+grpc_py_binary(
+  name = "test_tcp_connect",
+  srcs = ["test_tcp_connect.py"],
+  testonly = True,
+)
+
 generate_resolver_component_tests()

test/cpp/naming/generate_resolver_component_tests.bzl

@@ -55,6 +55,8 @@ def generate_resolver_component_tests():
             ":resolver_component_tests_runner",
             ":resolver_component_test%s" % unsecure_build_config_suffix,
             ":test_dns_server",
+            ":test_dns_resolver",
+            ":test_tcp_connect",
             "resolver_test_record_groups.yaml", # include the transitive dependency so that the dns sever py binary can locate this
         ],
         args = [

test/cpp/naming/resolver_component_tests_runner.sh

@@ -22,8 +22,10 @@ FLAGS_test_bin_path=$(echo "$1" | grep '\--test_bin_path=' | cut -d "=" -f 2)
 FLAGS_dns_server_bin_path=$(echo "$2" | grep '\--dns_server_bin_path=' | cut -d "=" -f 2)
 FLAGS_records_config_path=$(echo "$3" | grep '\--records_config_path=' | cut -d "=" -f 2)
 FLAGS_test_dns_server_port=$(echo "$4" | grep '\--test_dns_server_port=' | cut -d "=" -f 2)
+FLAGS_test_dns_resolver_bin_path=$(echo "$5" | grep '\--test_dns_resolver_bin_path=' | cut -d "=" -f 2)
+FLAGS_test_tcp_connect_bin_path=$(echo "$6" | grep '\--test_tcp_connect_bin_path=' | cut -d "=" -f 2)
 
-for cmd_arg in "$FLAGS_test_bin_path" "$FLAGS_dns_server_bin_path" "$FLAGS_records_config_path" "$FLAGS_test_dns_server_port"; do
+for cmd_arg in "$FLAGS_test_bin_path" "$FLAGS_dns_server_bin_path" "$FLAGS_records_config_path" "$FLAGS_test_dns_server_port" "$FLAGS_test_dns_resolver_bin_path" "$FLAGS_test_tcp_connect_bin_path"; do
   if [[ "$cmd_arg" == "" ]]; then
     echo "Missing a CMD arg" && exit 1
   fi
@@ -41,10 +43,10 @@ echo "Local DNS server started. PID: $DNS_SERVER_PID"
 # Health check local DNS server TCP and UDP ports
 for ((i=0;i<30;i++));
 do
-  echo "Retry health-check DNS query to local DNS server over tcp and udp"
+  echo "Retry health-check local DNS server by attempting a DNS query and TCP handshake"
   RETRY=0
-  dig A health-check-local-dns-server-is-alive.resolver-tests.grpctestingexp. @localhost -p "$FLAGS_test_dns_server_port" +tries=1 +timeout=1 | grep '123.123.123.123' || RETRY=1
-  dig A health-check-local-dns-server-is-alive.resolver-tests.grpctestingexp. @localhost -p "$FLAGS_test_dns_server_port" +tries=1 +timeout=1 +tcp | grep '123.123.123.123' || RETRY=1
+  $FLAGS_test_dns_resolver_bin_path -s 127.0.0.1 -p "$FLAGS_test_dns_server_port" -n health-check-local-dns-server-is-alive.resolver-tests.grpctestingexp. -t 1 | grep '123.123.123.123' || RETRY=1
+  $FLAGS_test_tcp_connect_bin_path -s 127.0.0.1 -p "$FLAGS_test_dns_server_port" -t 1 || RETRY=1
   if [[ "$RETRY" == 0 ]]; then
     break
   fi;

test/cpp/naming/resolver_component_tests_runner_invoker.cc

@@ -102,14 +102,18 @@ namespace testing {
 void InvokeResolverComponentTestsRunner(std::string test_runner_bin_path,
                                         std::string test_bin_path,
                                         std::string dns_server_bin_path,
-                                        std::string records_config_path) {
+                                        std::string records_config_path,
+                                        std::string test_dns_resolver_bin_path,
+                                        std::string test_tcp_connect_bin_path) {
   int test_dns_server_port = grpc_pick_unused_port_or_die();
 
   SubProcess* test_driver = new SubProcess(
       {test_runner_bin_path, "--test_bin_path=" + test_bin_path,
        "--dns_server_bin_path=" + dns_server_bin_path,
        "--records_config_path=" + records_config_path,
-       "--test_dns_server_port=" + std::to_string(test_dns_server_port)});
+       "--test_dns_server_port=" + std::to_string(test_dns_server_port),
+       "--test_dns_resolver_bin_path=" + test_dns_resolver_bin_path,
+       "--test_tcp_connect_bin_path=" + test_tcp_connect_bin_path});
   gpr_mu test_driver_mu;
   gpr_mu_init(&test_driver_mu);
   gpr_cv test_driver_cv;
@@ -171,7 +175,8 @@ int main(int argc, char** argv) {
     grpc::testing::InvokeResolverComponentTestsRunner(
         bin_dir + "/resolver_component_tests_runner",
         bin_dir + "/" + FLAGS_test_bin_name, bin_dir + "/test_dns_server",
-        bin_dir + "/resolver_test_record_groups.yaml");
+        bin_dir + "/resolver_test_record_groups.yaml",
+        bin_dir + "/test_dns_resolver", bin_dir + "/test_tcp_connect");
   } else {
     // Get the current binary's directory relative to repo root to invoke the
     // correct build config (asan/tsan/dbg, etc.).
@@ -181,7 +186,9 @@ int main(int argc, char** argv) {
         "test/cpp/naming/resolver_component_tests_runner.sh",
         bin_dir + "/" + FLAGS_test_bin_name,
         "test/cpp/naming/test_dns_server.py",
-        "test/cpp/naming/resolver_test_record_groups.yaml");
+        "test/cpp/naming/resolver_test_record_groups.yaml",
+        "test/cpp/naming/test_dns_resolver.py",
+        "test/cpp/naming/test_tcp_connect.py");
   }
   grpc_shutdown();
   return 0;

test/cpp/naming/test_dns_resolver.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python2.7
+# Copyright 2015 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Makes DNS queries for A records to specified servers"""
+
+import argparse
+import signal
+import twisted.internet.task as task
+import twisted.names.client as client
+
+def main():
+  argp = argparse.ArgumentParser(description='Make DNS queries for A records')
+  argp.add_argument('-s', '--server_host', default='127.0.0.1', type=str,
+                    help='Host for DNS server to listen on for TCP and UDP.')
+  argp.add_argument('-p', '--server_port', default=53, type=int,
+                    help='Port that the DNS server is listening on.')
+  argp.add_argument('-n', '--qname', default=None, type=str,
+                    help=('Name of the record to query for. '))
+  argp.add_argument('-t', '--timeout', default=1, type=int,
+                    help=('Force process exit after this number of seconds.'))
+  args = argp.parse_args()
+  signal.alarm(args.timeout)
+  def OnResolverResultAvailable(result):
+    answers, authority, additional = result
+    for a in answers:
+      print(a.payload)
+  def BeginQuery(reactor, qname):
+    servers = [(args.server_host, args.server_port)]
+    resolver = client.Resolver(servers=servers)
+    deferred_result = resolver.lookupAddress(args.qname)
+    deferred_result.addCallback(OnResolverResultAvailable)
+    return deferred_result
+  task.react(BeginQuery, [args.qname])
+
+if __name__ == '__main__':
+  main()

test/cpp/naming/test_tcp_connect.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python2.7
+# Copyright 2015 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Opens a TCP connection to a specified server and then exits."""
+
+import argparse
+import signal
+import socket
+
+def main():
+  argp = argparse.ArgumentParser(description='Open a TCP handshake to a server')
+  argp.add_argument('-s', '--server_host', default=None, type=str,
+                    help='Server host name or IP.')
+  argp.add_argument('-p', '--server_port', default=0, type=int,
+                    help='Port that the server is listening on.')
+  argp.add_argument('-t', '--timeout', default=1, type=int,
+                    help='Force process exit after this number of seconds.')
+  args = argp.parse_args()
+  signal.alarm(args.timeout)
+  socket.create_connection([args.server_host, args.server_port])
+
+if __name__ == '__main__':
+  main()