add package contrib/rpc/grpcx (#2169)

example/rpc/grpcx/basic/service/service_echo.go

@@ -0,0 +1,27 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package service
+
+import (
+	"fmt"
+
+	"context"
+
+	"github.com/gogf/gf/example/rpc/grpcx/basic/protocol"
+	"github.com/gogf/gf/v2/frame/g"
+	"github.com/gogf/gf/v2/os/gcmd"
+)
+
+// Echo is the service for echo.
+type Echo struct{}
+
+// Say implements the protobuf.EchoServer interface.
+func (s *Echo) Say(ctx context.Context, r *protocol.SayReq) (*protocol.SayRes, error) {
+	g.Log().Print(ctx, "Received:", r.Content)
+	text := fmt.Sprintf(`%s: > %s`, gcmd.GetOpt("node", "default"), r.Content)
+	return &protocol.SayRes{Content: text}, nil
+}