Merge pull request #16862 from apolcyn/convert_tests_to_cares

Switch the default DNS resolver from native to c-ares

src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc

@@ -472,7 +472,7 @@ static grpc_address_resolver_vtable ares_resolver = {
     grpc_resolve_address_ares, blocking_resolve_address_ares};
 
 static bool should_use_ares(const char* resolver_env) {
-  return resolver_env != nullptr && gpr_stricmp(resolver_env, "ares") == 0;
+  return resolver_env == nullptr || gpr_stricmp(resolver_env, "ares") == 0;
 }
 
 void grpc_resolver_dns_ares_init() {

templates/test/cpp/naming/resolver_component_tests_defs.include

@@ -55,7 +55,6 @@ if cur_resolver and cur_resolver != 'ares':
       'needs to use GRPC_DNS_RESOLVER=ares.'))
   test_runner_log('Exit 1 without running tests.')
   sys.exit(1)
-os.environ.update({'GRPC_DNS_RESOLVER': 'ares'})
 os.environ.update({'GRPC_TRACE': 'cares_resolver'})
 
 def wait_until_dns_server_is_up(args,

test/core/client_channel/resolvers/dns_resolver_test.cc

@@ -22,6 +22,8 @@
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "test/core/util/test_config.h"
 
@@ -72,12 +74,13 @@ int main(int argc, char** argv) {
   test_succeeds(dns, "dns:10.2.1.1:1234");
   test_succeeds(dns, "dns:www.google.com");
   test_succeeds(dns, "dns:///www.google.com");
-  if (grpc_resolve_address == grpc_resolve_address_ares) {
-    test_succeeds(dns, "dns://8.8.8.8/8.8.8.8:8888");
-  } else {
+  char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver_env != nullptr && gpr_stricmp(resolver_env, "native") == 0) {
     test_fails(dns, "dns://8.8.8.8/8.8.8.8:8888");
+  } else {
+    test_succeeds(dns, "dns://8.8.8.8/8.8.8.8:8888");
   }
-
+  gpr_free(resolver_env);
   {
     grpc_core::ExecCtx exec_ctx;
     GRPC_COMBINER_UNREF(g_combiner, "test");

test/core/surface/concurrent_connectivity_test.cc

@@ -44,7 +44,7 @@
 #define NUM_OUTER_LOOPS 10
 #define NUM_INNER_LOOPS 10
 #define DELAY_MILLIS 10
-#define POLL_MILLIS 3000
+#define POLL_MILLIS 15000
 
 #define NUM_OUTER_LOOPS_SHORT_TIMEOUTS 10
 #define NUM_INNER_LOOPS_SHORT_TIMEOUTS 100

test/cpp/naming/resolver_component_tests_runner.py

@@ -55,7 +55,6 @@ if cur_resolver and cur_resolver != 'ares':
       'needs to use GRPC_DNS_RESOLVER=ares.'))
   test_runner_log('Exit 1 without running tests.')
   sys.exit(1)
-os.environ.update({'GRPC_DNS_RESOLVER': 'ares'})
 os.environ.update({'GRPC_TRACE': 'cares_resolver'})
 
 def wait_until_dns_server_is_up(args,