snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

examples/features/dualstack/server/main.go

@@ -0,0 +1,84 @@
+/*
+ *
+ * Copyright 2025 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Binary server is a server for the dualstack example.
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"sync"
+
+	"google.golang.org/grpc"
+	hwpb "google.golang.org/grpc/examples/helloworld/helloworld"
+)
+
+type greeterServer struct {
+	hwpb.UnimplementedGreeterServer
+	addressType string
+	address     string
+	port        uint32
+}
+
+func (s *greeterServer) SayHello(_ context.Context, req *hwpb.HelloRequest) (*hwpb.HelloReply, error) {
+	return &hwpb.HelloReply{
+		Message: fmt.Sprintf("Hello %s from server<%d> type: %s)", req.GetName(), s.port, s.addressType),
+	}, nil
+}
+
+func main() {
+	servers := []*greeterServer{
+		{
+			addressType: "both IPv4 and IPv6",
+			address:     "[::]",
+			port:        50051,
+		},
+		{
+			addressType: "IPv4 only",
+			address:     "127.0.0.1",
+			port:        50052,
+		},
+		{
+			addressType: "IPv6 only",
+			address:     "[::1]",
+			port:        50053,
+		},
+	}
+
+	var wg sync.WaitGroup
+	for _, server := range servers {
+		bindAddr := fmt.Sprintf("%s:%d", server.address, server.port)
+		lis, err := net.Listen("tcp", bindAddr)
+		if err != nil {
+			log.Fatalf("failed to listen: %v", err)
+		}
+		s := grpc.NewServer()
+		hwpb.RegisterGreeterServer(s, server)
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if err := s.Serve(lis); err != nil {
+				log.Panicf("failed to serve: %v", err)
+			}
+		}()
+		log.Printf("serving on %s\n", bindAddr)
+	}
+	wg.Wait()
+}