Surface user agent by default

include/grpc/impl/codegen/grpc_types.h

@@ -342,7 +342,8 @@ typedef struct {
   "grpc.disable_client_authority_filter"
 /** If set to zero, disables use of http proxies. Enabled by default. */
 #define GRPC_ARG_ENABLE_HTTP_PROXY "grpc.enable_http_proxy"
-/** If set to non zero, surfaces the user agent string to the server. */
+/** If set to non zero, surfaces the user agent string to the server. User
+    agent is surfaced by default. */
 #define GRPC_ARG_SURFACE_USER_AGENT "grpc.surface_user_agent"
 /** \} */
 

src/core/ext/filters/http/server/http_server_filter.cc

@@ -445,7 +445,7 @@ static grpc_error* hs_init_channel_elem(grpc_channel_element* elem,
   chand->surface_user_agent = grpc_channel_arg_get_bool(
       grpc_channel_args_find(args->channel_args,
                              const_cast<char*>(GRPC_ARG_SURFACE_USER_AGENT)),
-      false);
+      true);
   return GRPC_ERROR_NONE;
 }
 

test/core/end2end/tests/workaround_cronet_compression.cc

@@ -149,15 +149,6 @@ static void request_with_payload_template(
     arg.value.string = user_agent_override;
     client_args = grpc_channel_args_copy_and_add(client_args_old, &arg, 1);
     grpc_channel_args_destroy(client_args_old);
-    // force grpc lib to pass the user agent back up to server.
-    grpc_channel_args* server_args_old = server_args;
-    grpc_arg server_arg;
-    server_arg.key = const_cast<char*>(GRPC_ARG_SURFACE_USER_AGENT);
-    server_arg.type = GRPC_ARG_INTEGER;
-    server_arg.value.integer = 1;
-    server_args =
-        grpc_channel_args_copy_and_add(server_args_old, &server_arg, 1);
-    grpc_channel_args_destroy(server_args_old);
   }
 
   f = begin_test(config, test_name, client_args, server_args);

test/cpp/end2end/end2end_test.cc

@@ -244,17 +244,15 @@ class End2endTest : public ::testing::TestWithParam<TestScenario> {
     BuildAndStartServer(processor);
   }
 
-  void RestartServer(const std::shared_ptr<AuthMetadataProcessor>& processor,
-                     bool surface_user_agent = false) {
+  void RestartServer(const std::shared_ptr<AuthMetadataProcessor>& processor) {
     if (is_server_started_) {
       server_->Shutdown();
-      BuildAndStartServer(processor, surface_user_agent);
+      BuildAndStartServer(processor);
     }
   }
 
   void BuildAndStartServer(
-      const std::shared_ptr<AuthMetadataProcessor>& processor,
-      bool surface_user_agent = false) {
+      const std::shared_ptr<AuthMetadataProcessor>& processor) {
     ServerBuilder builder;
     ConfigureServerBuilder(&builder);
     auto server_creds = GetCredentialsProvider()->GetServerCredentials(
@@ -270,9 +268,6 @@ class End2endTest : public ::testing::TestWithParam<TestScenario> {
     builder.SetSyncServerOption(ServerBuilder::SyncServerOption::NUM_CQS, 4);
     builder.SetSyncServerOption(
         ServerBuilder::SyncServerOption::CQ_TIMEOUT_MSEC, 10);
-    if (surface_user_agent) {
-      builder.AddChannelArgument(GRPC_ARG_SURFACE_USER_AGENT, 1);
-    }
 
     server_ = builder.BuildAndStart();
     is_server_started_ = true;
@@ -669,8 +664,6 @@ TEST_P(End2endTest, SimpleRpcWithCustomUserAgentPrefix) {
   }
   user_agent_prefix_ = "custom_prefix";
   ResetStub();
-  RestartServer(std::shared_ptr<AuthMetadataProcessor>(), true);
-  ResetChannel();
   EchoRequest request;
   EchoResponse response;
   request.set_message("Hello hello hello hello");