Make c-ares resolver unit tests runnable under python3

templates/test/cpp/naming/resolver_component_tests_defs.include

@@ -77,9 +77,9 @@ def wait_until_dns_server_is_up(args,
           '--server_host', '127.0.0.1',
           '--server_port', str(args.dns_server_port)]),
           stdout=subprocess.PIPE)
-      dns_resolver_stdout, _ = dns_resolver_subprocess.communicate()
+      dns_resolver_stdout, _ = dns_resolver_subprocess.communicate(str.encode('ascii'))
       if dns_resolver_subprocess.returncode == 0:
-        if '123.123.123.123' in dns_resolver_stdout:
+        if bytes('123.123.123.123'.encode('ascii')) in dns_resolver_stdout:
           test_runner_log(('DNS server is up! '
                            'Successfully reached it over UDP and TCP.'))
         return

test/cpp/naming/resolver_component_tests_runner.py

@@ -77,9 +77,9 @@ def wait_until_dns_server_is_up(args,
           '--server_host', '127.0.0.1',
           '--server_port', str(args.dns_server_port)]),
           stdout=subprocess.PIPE)
-      dns_resolver_stdout, _ = dns_resolver_subprocess.communicate()
+      dns_resolver_stdout, _ = dns_resolver_subprocess.communicate(str.encode('ascii'))
       if dns_resolver_subprocess.returncode == 0:
-        if '123.123.123.123' in dns_resolver_stdout:
+        if bytes('123.123.123.123'.encode('ascii')) in dns_resolver_stdout:
           test_runner_log(('DNS server is up! '
                            'Successfully reached it over UDP and TCP.'))
         return

test/cpp/naming/utils/dns_server.py

@@ -53,6 +53,7 @@ def start_local_dns_server(args):
     all_records = {}
 
     def _push_record(name, r):
+        name = bytes(name.encode('ascii'))
         print('pushing record: |%s|' % name)
         if all_records.get(name) is not None:
             all_records[name].append(r)
@@ -60,6 +61,7 @@ def start_local_dns_server(args):
         all_records[name] = [r]
 
     def _maybe_split_up_txt_data(name, txt_data, r_ttl):
+        txt_data = bytes(txt_data.encode('ascii'))
         start = 0
         txt_data_list = []
         while len(txt_data[start:]) > 0:
@@ -93,8 +95,8 @@ def start_local_dns_server(args):
                     p = int(p)
                     w = int(w)
                     port = int(port)
-                    target_full_name = '%s.%s' % (target, common_zone_name)
+                    target_full_name = bytes(
-                    r_data = '%s %s %s %s' % (p, w, port, target_full_name)
+                        ('%s.%s' % (target, common_zone_name)).encode('ascii'))
                     _push_record(
                         record_full_name,
                         dns.Record_SRV(p, w, port, target_full_name, ttl=r_ttl))
@@ -107,9 +109,9 @@ def start_local_dns_server(args):
     # Server health check record
     _push_record(_SERVER_HEALTH_CHECK_RECORD_NAME,
                  dns.Record_A(_SERVER_HEALTH_CHECK_RECORD_DATA, ttl=0))
-    soa_record = dns.Record_SOA(mname=common_zone_name)
+    soa_record = dns.Record_SOA(mname=bytes(common_zone_name.encode('ascii')))
     test_domain_com = NoFileAuthority(
-        soa=(common_zone_name, soa_record),
+        soa=(bytes(common_zone_name.encode('ascii')), soa_record),
         records=all_records,
     )
     server = twisted.names.server.DNSServerFactory(