Adding Proto Reflection and Health Check to basic C++ example server

And ensuring the example can be built and ran via
bazel, make, and cmake.

examples/BUILD

@@ -114,6 +114,7 @@ cc_binary(
     deps = [
         ":helloworld_cc_grpc",
         "//:grpc++",
+        "//:grpc++_reflection",
     ],
 )
 

examples/cpp/helloworld/CMakeLists.txt

@@ -54,6 +54,7 @@ if(GRPC_AS_SUBMODULE)
   # After using add_subdirectory, we can now use the grpc targets directly from
   # this build.
   set(_PROTOBUF_LIBPROTOBUF libprotobuf)
+  set(_REFLECTION grpc++_reflection)
   if(CMAKE_CROSSCOMPILING)
     find_program(_PROTOBUF_PROTOC protoc)
   else()
@@ -84,6 +85,7 @@ elseif(GRPC_FETCHCONTENT)
   # Since FetchContent uses add_subdirectory under the hood, we can use
   # the grpc targets directly from this build.
   set(_PROTOBUF_LIBPROTOBUF libprotobuf)
+  set(_REFLECTION grpc++_reflection)
   set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)
   set(_GRPC_GRPCPP_UNSECURE grpc++_unsecure)
   if(CMAKE_CROSSCOMPILING)
@@ -102,6 +104,7 @@ else()
   message(STATUS "Using protobuf ${protobuf_VERSION}")
 
   set(_PROTOBUF_LIBPROTOBUF protobuf::libprotobuf)
+  set(_REFLECTION gRPC::grpc++_reflection)
   if(CMAKE_CROSSCOMPILING)
     find_program(_PROTOBUF_PROTOC protoc)
   else()
@@ -151,6 +154,7 @@ foreach(_target
     ${hw_proto_srcs}
     ${hw_grpc_srcs})
   target_link_libraries(${_target}
+    ${_REFLECTION}
     ${_GRPC_GRPCPP_UNSECURE}
     ${_PROTOBUF_LIBPROTOBUF})
 endforeach()

examples/cpp/helloworld/greeter_server.cc

@@ -21,6 +21,8 @@
 #include <string>
 
 #include <grpcpp/grpcpp.h>
+#include <grpcpp/health_check_service_interface.h>
+#include <grpcpp/ext/proto_server_reflection_plugin.h>
 
 #ifdef BAZEL_BUILD
 #include "examples/protos/helloworld.grpc.pb.h"
@@ -50,6 +52,8 @@ void RunServer() {
   std::string server_address("0.0.0.0:50051");
   GreeterServiceImpl service;
 
+  grpc::EnableDefaultHealthCheckService(true);
+  grpc::reflection::InitProtoReflectionServerBuilderPlugin();
   ServerBuilder builder;
   // Listen on the given address without any authentication mechanism.
   builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());