最近公司需要无感知基于服务代号来实现通信, 并监控和管理通信连接，目前公司使用的是如下的逻辑(当然逻辑简化了，但是思想不变)

简单的原理图

代理服务的实现

创建 tls tcp 服务, 用于grpc client 和 grpc service 通信

func Run() error {// 创建 CA证书 用于 tls 连接ca, err := private_keys.NewCA("127.0.0.1")if err != nil {log.Fatal(err)}serverCA, err := tls.X509KeyPair(ca.CertPem(), ca.KeyPem())if err != nil {log.Fatal(err)}tlsServerConfig := &tls.Config{Certificates: []tls.Certificate{serverCA},}// 创建 带 tls 的tcp服务listener, err := tls.Listen("tcp", fmt.Sprintf(":%d", Port), tlsServerConfig)if err != nil {log.Printf("Error tcp listening on port %d: %v\n", Port, err)return err}fmt.Println("TCP Listening on port ", Port, "; successfully")for {conn, err := listener.Accept()if err != nil {log.Printf("Error accepting connection: %v\n", err)return err}fmt.Println("tcp new connection")// 处理请求go forwardCommunication(conn)}return nil
}func forwardCommunication(conn net.Conn) error {// 首次连接上的时候，通信告诉 tcp server 是客户端连接还是服务端连接bufBytes, err := ReadData(conn)if err != nil {return err}device := &Device{}err = json.Unmarshal(bufBytes, device)if err != nil {log.Printf("Error unmarshalling json: %v\n", err)return err}
}

保存 与 代理服务建立的 grpc service 的连接

func server(deviceID string, conn net.Conn) error {sendData, err := json.Marshal(OK{Code: 1})if err != nil {log.Printf("Error marshalling json: %v\n", err)return err}sendData = append(sendData, '@')_, err = conn.Write(sendData)if err != nil {log.Printf("Error writing to connection: %v\n", err)return err}// 保存 grpc 服务的 dial connectsetConnMap(deviceID, conn)return nil
}

保存 grpc client dial 的连接

client 连接上了的时候告诉 tcp server, 要连接哪个 grpc service

从 保存的conn 中查询是否有 相关的连接

如果有，则 通过 io.Copy 来让grpc client 与 grpc service 通信

func client(deviceID string, conn net.Conn) error {toConn := GetConn(deviceID)successCode := 0if toConn == nil {successCode = -1}sendData, _ := json.Marshal(OK{Code: successCode})_, err := conn.Write(append(sendData, MessageEnd))if err != nil {log.Printf("Error writing to connection: %v\n", err)}if successCode < 0 {conn.Close()return err}go func() {_, err := io.Copy(toConn, conn)if err != nil {log.Printf("client toConn error reading from connection: %v\n", err)}log.Printf("toConn conn closed.\n")return}()go func() {_, err := io.Copy(conn, toConn)if err != nil {log.Printf("client conn error reading from connection: %v\n", err)}log.Printf("conn toConn closed.\n")}()fmt.Println("Client connected to device", deviceID)return nil
}

代码地址

https://github.com/wanmei002/websocket-reverse-proxy