Merge pull request #937 from menghanl/reflection_tutorial

Add server-reflection-tutorial.md

examples/helloworld/greeter_server/main.go

@@ -40,6 +40,7 @@ import (
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 	pb "google.golang.org/grpc/examples/helloworld/helloworld"
+	"google.golang.org/grpc/reflection"
 )
 
 const (
@@ -61,6 +62,8 @@ func main() {
 	}
 	s := grpc.NewServer()
 	pb.RegisterGreeterServer(s, &server{})
+	// Register reflection service on gRPC server.
+	reflection.Register(s)
 	if err := s.Serve(lis); err != nil {
 		log.Fatalf("failed to serve: %v", err)
 	}