xref: /aosp_15_r20/external/grpc-grpc/examples/cpp/helloworld/xds_greeter_server.cc (revision cc02d7e222339f7a4f6ba5f422e6413f4bd931f2)
1 /*
2  *
3  * Copyright 2021 gRPC authors.
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *     http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  */
18 
19 #include <iostream>
20 #include <memory>
21 #include <string>
22 
23 #include "absl/flags/flag.h"
24 #include "absl/flags/parse.h"
25 #include "absl/strings/str_cat.h"
26 
27 #include <grpcpp/ext/admin_services.h>
28 #include <grpcpp/ext/proto_server_reflection_plugin.h>
29 #include <grpcpp/grpcpp.h>
30 #include <grpcpp/health_check_service_interface.h>
31 #include <grpcpp/xds_server_builder.h>
32 
33 #ifdef BAZEL_BUILD
34 #include "examples/protos/helloworld.grpc.pb.h"
35 #else
36 #include "helloworld.grpc.pb.h"
37 #endif
38 
39 ABSL_FLAG(int32_t, port, 50051, "Server port for service.");
40 ABSL_FLAG(int32_t, maintenance_port, 50052,
41           "Server port for maintenance if --secure is used.");
42 ABSL_FLAG(bool, secure, true, "Secure mode");
43 
44 using grpc::Server;
45 using grpc::ServerBuilder;
46 using grpc::ServerContext;
47 using grpc::Status;
48 using helloworld::Greeter;
49 using helloworld::HelloReply;
50 using helloworld::HelloRequest;
51 
52 // Logic and data behind the server's behavior.
53 class GreeterServiceImpl final : public Greeter::Service {
SayHello(ServerContext * context,const HelloRequest * request,HelloReply * reply)54   Status SayHello(ServerContext* context, const HelloRequest* request,
55                   HelloReply* reply) override {
56     std::string prefix("Hello ");
57     reply->set_message(prefix + request->name());
58     return Status::OK;
59   }
60 };
61 
RunServer()62 void RunServer() {
63   grpc::EnableDefaultHealthCheckService(true);
64   grpc::reflection::InitProtoReflectionServerBuilderPlugin();
65   int port = absl::GetFlag(FLAGS_port);
66   int maintenance_port = absl::GetFlag(FLAGS_maintenance_port);
67   grpc::XdsServerBuilder xds_builder;
68   ServerBuilder builder;
69   std::unique_ptr<Server> xds_enabled_server;
70   std::unique_ptr<Server> server;
71   GreeterServiceImpl service;
72   // Register "service" as the instance through which we'll communicate with
73   // clients. In this case it corresponds to an *synchronous* service.
74   xds_builder.RegisterService(&service);
75   if (absl::GetFlag(FLAGS_secure)) {
76     // Listen on the given address with XdsServerCredentials and a fallback of
77     // InsecureServerCredentials
78     xds_builder.AddListeningPort(
79         absl::StrCat("0.0.0.0:", port),
80         grpc::XdsServerCredentials(grpc::InsecureServerCredentials()));
81     xds_enabled_server = xds_builder.BuildAndStart();
82     gpr_log(GPR_INFO, "Server starting on 0.0.0.0:%d", port);
83     grpc::AddAdminServices(&builder);
84     // For the maintenance server, do not use any authentication mechanism.
85     builder.AddListeningPort(absl::StrCat("0.0.0.0:", maintenance_port),
86                              grpc::InsecureServerCredentials());
87     server = builder.BuildAndStart();
88     gpr_log(GPR_INFO, "Maintenance server listening on 0.0.0.0:%d",
89             maintenance_port);
90   } else {
91     grpc::AddAdminServices(&xds_builder);
92     // Listen on the given address without any authentication mechanism.
93     builder.AddListeningPort(absl::StrCat("0.0.0.0:", port),
94                              grpc::InsecureServerCredentials());
95     server = xds_builder.BuildAndStart();
96     gpr_log(GPR_INFO, "Server listening on 0.0.0.0:%d", port);
97   }
98 
99   // Wait for the server to shutdown. Note that some other thread must be
100   // responsible for shutting down the server for this call to ever return.
101   server->Wait();
102 }
103 
main(int argc,char ** argv)104 int main(int argc, char** argv) {
105   absl::ParseCommandLine(argc, argv);
106   RunServer();
107   return 0;
108 }
109