1 files changed, 19 insertions, 3 deletions
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index d227c19c43..97cd0486a9 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -44,6 +44,7 @@
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/support/backoff.h"
+#include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
 
 #define GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS 1
@@ -113,8 +114,9 @@ static void dns_shutdown_locked(grpc_exec_ctx *exec_ctx,
   }
   if (r->next_completion != NULL) {
     *r->target_result = NULL;
-    grpc_closure_sched(exec_ctx, r->next_completion,
-                       GRPC_ERROR_CREATE("Resolver Shutdown"));
+    grpc_closure_sched(
+        exec_ctx, r->next_completion,
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Resolver Shutdown"));
     r->next_completion = NULL;
   }
 }
@@ -303,7 +305,21 @@ static grpc_resolver_factory *dns_resolver_factory_create() {
 }
 
 void grpc_resolver_dns_native_init(void) {
-  grpc_register_resolver_type(dns_resolver_factory_create());
+  char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver != NULL && gpr_stricmp(resolver, "native") == 0) {
+    gpr_log(GPR_DEBUG, "Using native dns resolver");
+    grpc_register_resolver_type(dns_resolver_factory_create());
+  } else {
+    grpc_resolver_factory *existing_factory =
+        grpc_resolver_factory_lookup("dns");
+    if (existing_factory == NULL) {
+      gpr_log(GPR_DEBUG, "Using native dns resolver");
+      grpc_register_resolver_type(dns_resolver_factory_create());
+    } else {
+      grpc_resolver_factory_unref(existing_factory);
+    }
+  }
+  gpr_free(resolver);
 }
 
 void grpc_resolver_dns_native_shutdown(void) {}