1. 增加grpc代码实现（websocket在grpc模式下有问题）

config.yml

@@ -0,0 +1,31 @@
+# config.yml
+
+# 服务器相关配置
+server:
+  app_listen_port: ":8089"
+  device_listen_port: ":7002"
+  instance_id: "" # 留空会自动生成 UUID, 也可以指定一个固定的ID
+  # [新增] 用于服务器间通信的 gRPC 配置
+  grpc_listen_addr: ":9090"
+  # 这个地址必须能被其他服务器实例访问到。
+  # 在 Docker/K8s 环境中, 这应该是服务名或 Pod IP。
+  grpc_advertise_addr: "192.168.5.193:9090"
+
+# 认证密钥配置
+auth:
+  app_access_secret: "D4tBb9Y0oHSXRAyHLHpdKfXAuNCyCZ45AZxKJOhMJMs="
+  device_relay_secret: "p+JtJ8aHlM1lDYu7UGFanX8ALVt1pM1BQmKTpqTJccs="
+
+# Redis 配置 (为下一步做准备)
+# 如果 enabled 为 false，我们的代码将退回使用内存 map，实现单机兼容
+redis:
+  enabled: true
+  addr: "118.178.183.78:6379"
+  password: "" # 留空表示没有密码
+  db: 1
+  session_ttl_seconds: 120 # 会话在 Redis 中的过期时间、
+  # [新增] 用于服务发现的 Key
+  # 一个 Redis Hash, 存储 instance_id -> grpc_addr 的映射
+  instance_registry_key: "relay_instances"
+  # 实例必须比这个 TTL 更快地发送心跳
+  instance_ttl_seconds: 15

config/config.go

@@ -0,0 +1,79 @@
+package config
+
+import (
+	"github.com/google/uuid"
+	"github.com/spf13/viper"
+	"log"
+	"strings"
+)
+
+// Config 结构体必须与 config.yml 的结构完全对应
+// 使用 `mapstructure` tag 来帮助 Viper 正确映射 YAML 键名到 Go 结构体字段
+type Config struct {
+	Server ServerConfig `mapstructure:"server"`
+	Auth   AuthConfig   `mapstructure:"auth"`
+	Redis  RedisConfig  `mapstructure:"redis"`
+}
+
+type ServerConfig struct {
+	AppListenPort    string `mapstructure:"app_listen_port"`
+	DeviceListenPort string `mapstructure:"device_listen_port"`
+
+	// [新增]
+	InstanceID        string `mapstructure:"instance_id"`
+	GrpcListenAddr    string `mapstructure:"grpc_listen_addr"`
+	GrpcAdvertiseAddr string `mapstructure:"grpc_advertise_addr"`
+}
+
+type AuthConfig struct {
+	AppAccessSecret   string `mapstructure:"app_access_secret"`
+	DeviceRelaySecret string `mapstructure:"device_relay_secret"`
+}
+
+type RedisConfig struct {
+	Enabled           bool   `mapstructure:"enabled"`
+	Addr              string `mapstructure:"addr"`
+	Password          string `mapstructure:"password"`
+	DB                int    `mapstructure:"db"`
+	SessionTTLSeconds int    `mapstructure:"session_ttl_seconds"` // 确保有这个字段
+
+	// [新增]
+	InstanceRegistryKey string `mapstructure:"instance_registry_key"`
+	InstanceTTLSeconds  int    `mapstructure:"instance_ttl_seconds"`
+}
+
+// Cfg 是一个全局变量，用于在项目的任何地方访问配置
+var Cfg *Config
+
+// LoadConfig 是初始化函数，负责读取和解析配置文件
+func LoadConfig() {
+	viper.SetConfigName("config")   // 配置文件名 (不带扩展名)
+	viper.SetConfigType("yml")      // 配置文件类型
+	viper.AddConfigPath(".")        // 在当前工作目录查找配置文件
+	viper.AddConfigPath("./config") // 也在 config 目录查找
+
+	// [关键] 开启环境变量支持
+	// 这允许你通过环境变量覆盖配置文件中的值
+	// 例如：SERVER_APP_LISTEN_ADDR=":9000" 会覆盖文件中的设置
+	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+	viper.AutomaticEnv()
+
+	// 读取配置文件
+	if err := viper.ReadInConfig(); err != nil {
+		// 如果配置文件没找到，也没关系，可能完全通过环境变量配置
+		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
+			log.Fatalf("Fatal error reading config file: %v", err)
+		}
+	}
+
+	// 将读取到的配置反序列化到 Cfg 结构体中
+	if err := viper.Unmarshal(&Cfg); err != nil {
+		log.Fatalf("Unable to decode config into struct: %v", err)
+	}
+
+	// [新增] 如果 instance_id 未配置，则自动生成
+	if Cfg.Server.InstanceID == "" {
+		Cfg.Server.InstanceID = uuid.New().String()
+	}
+	log.Printf("Configuration loaded. Server Instance ID: %s", Cfg.Server.InstanceID)
+}

go.mod

@@ -1,8 +1,34 @@
 module memobus_relay_server
 
-go 1.24
+go 1.24.0
+
+toolchain go1.24.2
 
 require (
 	github.com/golang-jwt/jwt/v5 v5.3.0
+	github.com/google/uuid v1.6.0
 	github.com/hashicorp/yamux v0.1.2
+	github.com/redis/go-redis/v9 v9.14.1
+	github.com/spf13/viper v1.21.0
+	google.golang.org/grpc v1.76.0
+)
+
+require (
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/sagikazarmark/locafero v0.11.0 // indirect
+	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
+	github.com/spf13/afero v1.15.0 // indirect
+	github.com/spf13/cast v1.10.0 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/net v0.42.0 // indirect
+	golang.org/x/sys v0.34.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250804133106-a7a43d27e69b // indirect
+	google.golang.org/protobuf v1.36.6 // indirect
 )

grpc/server.go

@@ -0,0 +1,360 @@
+// 文件: grpc/server.go
+package grpc
+
+import (
+	"bufio"
+	"io"
+	"log"
+	relaypb "memobus_relay_server/relay_server/proto"
+	"memobus_relay_server/session"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+// InternalRelayServer 实现了用于代理请求的 gRPC 服务
+type InternalRelayServer struct {
+	relaypb.UnimplementedInternalRelayServer
+}
+
+// NewInternalRelayServer 创建一个新的 gRPC 服务实例
+func NewInternalRelayServer() *InternalRelayServer {
+	return &InternalRelayServer{}
+}
+
+// ProxyRequest 是核心的 gRPC 流处理器，实现了完整的请求代理和流式响应
+func (s *InternalRelayServer) ProxyRequest(stream relaypb.InternalRelay_ProxyRequestServer) error {
+	// --- 1. 接收和解析请求头 ---
+	headerMsg, err := stream.Recv()
+	if err != nil {
+		log.Printf("ERROR (gRPC): Failed to receive initial header: %v", err)
+		return status.Errorf(codes.InvalidArgument, "failed to receive header: %v", err)
+	}
+	header := headerMsg.GetHeader()
+	if header == nil {
+		return status.Errorf(codes.InvalidArgument, "first message must be a header")
+	}
+
+	// [新增调试日志]
+	if header.Headers["Upgrade"] == "websocket" {
+		log.Printf("DEBUG (WebSocket): gRPC server received WebSocket upgrade request. Headers: Connection='%s', Upgrade='%s'", header.Headers["Connection"], header.Headers["Upgrade"])
+	}
+
+	// 检查是否是 WebSocket 握手请求
+	isWebSocket := header.Headers["Upgrade"] == "websocket" && strings.Contains(strings.ToLower(header.Headers["Connection"]), "upgrade")
+
+	pathParts := strings.SplitN(strings.TrimPrefix(header.Url, "/"), "/", 3)
+	if len(pathParts) < 2 {
+		return status.Errorf(codes.InvalidArgument, "invalid URL format in gRPC header")
+	}
+	deviceSN := pathParts[1]
+	appUserID := header.GetAppUserId()
+
+	if appUserID == "" {
+		return status.Errorf(codes.InvalidArgument, "app_user_id is missing in gRPC header")
+	}
+
+	log.Printf("gRPC Proxy: Handling request for device '%s' from user '%s'", deviceSN, appUserID)
+
+	// --- 2. 查找本地会话并进行授权检查 ---
+	sessionInfo, ok := session.GlobalManager.GetLocalSession(deviceSN)
+	if !ok {
+		return status.Errorf(codes.NotFound, "device '%s' not connected to this instance", deviceSN)
+	}
+
+	if sessionInfo.UserID != appUserID {
+		log.Printf("Forbidden (gRPC): User '%s' attempted to access device '%s' owned by '%s'", appUserID, deviceSN, sessionInfo.UserID)
+		return sendForbiddenResponse(stream)
+	}
+
+	log.Printf("gRPC Proxy: Handling request for device '%s' from user '%s'", deviceSN, appUserID)
+
+	// --- 3. [核心修改] 根据请求类型进行分流 ---
+	if isWebSocket {
+		log.Println("gRPC Proxy: Detected WebSocket request, diverting to transparent proxy handler.")
+		return s.handleWebSocketProxy(stream, sessionInfo, deviceSN, header)
+	} else {
+		// 如果是普通 HTTP, 调用原来的 ReverseProxy 处理器
+		log.Println("gRPC Proxy: Detected HTTP request, using ReverseProxy handler.")
+		// 注意：我把原来的 ProxyRequest 逻辑提取到了一个新函数中，以保持整洁
+		return s.handleHTTPProxy(stream, sessionInfo, deviceSN, header)
+	}
+}
+
+func (s *InternalRelayServer) handleWebSocketProxy(stream relaypb.InternalRelay_ProxyRequestServer, sessionInfo *session.SessionInfo, deviceSN string, header *relaypb.ProxyRequestHeader) error {
+	// 1. 打开到后端 (yamux) 的连接
+	backendConn, err := sessionInfo.Session.Open()
+	if err != nil {
+		log.Printf("ERROR (WebSocket Proxy): Failed to dial backend: %v", err)
+		return status.Errorf(codes.Internal, "failed to connect to backend service")
+	}
+	defer backendConn.Close()
+
+	// 2. 重建原始的 HTTP 升级请求
+	req := httptest.NewRequest(header.Method, "http://internal-proxy"+header.Url, nil)
+	for k, v := range header.Headers {
+		req.Header.Set(k, v)
+	}
+	req.Host = "immich-internal" // 模拟 ReverseProxy 的行为
+	pathParts := strings.SplitN(strings.TrimPrefix(req.URL.Path, "/"), "/", 3)
+	if len(pathParts) > 2 {
+		req.URL.Path = "/" + pathParts[2]
+	} else {
+		req.URL.Path = "/"
+	}
+
+	// 3. 将升级请求写入后端连接，发起握手
+	if err := req.Write(backendConn); err != nil {
+		log.Printf("ERROR (WebSocket Proxy): Failed to write upgrade request to backend: %v", err)
+		return status.Errorf(codes.Internal, "failed to send upgrade request to backend")
+	}
+
+	// 4. 读取后端的响应 (握手结果)
+	backendReader := bufio.NewReader(backendConn)
+	resp, err := http.ReadResponse(backendReader, req)
+	if err != nil {
+		log.Printf("ERROR (WebSocket Proxy): Failed to read handshake response from backend: %v", err)
+		return status.Errorf(codes.Internal, "failed to read handshake response from backend")
+	}
+
+	// 5. 将后端的握手响应通过 gRPC 发回给代理节点
+	respHeaderMsg := &relaypb.ProxyResponseMessage{
+		Payload: &relaypb.ProxyResponseMessage_Header{
+			Header: &relaypb.ProxyResponseHeader{
+				StatusCode: int32(resp.StatusCode),
+				Headers:    make(map[string]string),
+			},
+		},
+	}
+	for k, v := range resp.Header {
+		respHeaderMsg.GetHeader().Headers[k] = strings.Join(v, ",")
+	}
+	if err := stream.Send(respHeaderMsg); err != nil {
+		log.Printf("ERROR (WebSocket Proxy): Failed to send handshake response via gRPC: %v", err)
+		return err
+	}
+
+	// 6. 如果握手失败 (不是 101)，则流程结束
+	if resp.StatusCode != http.StatusSwitchingProtocols {
+		log.Printf("WARN (WebSocket Proxy): Backend returned non-101 status for upgrade: %d", resp.StatusCode)
+		return nil
+	}
+
+	log.Printf("WebSocket handshake for device %s successful. Starting bi-directional stream copy.", deviceSN)
+
+	// 7. 握手成功！现在在 gRPC 流和 yamux 流之间建立双向数据拷贝
+	errChan := make(chan error, 2)
+
+	// Goroutine 1: gRPC 请求流 (来自 App) -> yamux 流 (下行数据)
+	go func() {
+		// 这个方向的逻辑没有问题
+		for {
+			msg, err := stream.Recv()
+			if err == io.EOF {
+				backendConn.Close()
+				errChan <- nil
+				return
+			}
+			if err != nil {
+				errChan <- err
+				return
+			}
+			if chunk := msg.GetBodyChunk(); chunk != nil {
+				if _, err := backendConn.Write(chunk.Data); err != nil {
+					errChan <- err
+					return
+				}
+			}
+		}
+	}()
+
+	// Goroutine 2: yamux 流 (来自设备) -> gRPC 响应流 (上行数据)
+	go func() {
+		// [核心修正]
+		// 我们必须从 backendReader (而不是原始的 backendConn) 开始读取，
+		// 以确保 http.ReadResponse 预读到缓冲区的数据不会丢失。
+		// io.Copy 会首先清空 backendReader 的内部缓冲区，然后再继续从底层的 backendConn 读取。
+		if _, err := io.Copy(&grpcResponseWriter{stream: stream}, backendReader); err != nil {
+			// 过滤掉正常的连接关闭错误
+			if err != io.EOF && err != io.ErrClosedPipe && !strings.Contains(err.Error(), "use of closed") {
+				errChan <- err
+			} else {
+				errChan <- nil
+			}
+		} else {
+			errChan <- nil
+		}
+	}()
+
+	// 等待两个 goroutine 都结束
+	err1 := <-errChan
+	err2 := <-errChan
+
+	if err1 != nil && err1 != io.EOF {
+		log.Printf("WebSocket stream finished with error: %v", err1)
+		return err1
+	}
+	if err2 != nil && err2 != io.EOF {
+		log.Printf("WebSocket stream finished with error: %v", err2)
+		return err2
+	}
+
+	log.Printf("WebSocket stream for device %s finished gracefully.", deviceSN)
+	return nil
+}
+
+// [新增] handleHTTPProxy 包含了原来 ProxyRequest 的所有逻辑
+func (s *InternalRelayServer) handleHTTPProxy(stream relaypb.InternalRelay_ProxyRequestServer, sessionInfo *session.SessionInfo, deviceSN string, header *relaypb.ProxyRequestHeader) error {
+	// 这部分代码就是你之前工作正常的、使用 io.Pipe 和 ReverseProxy 的完整流式版本
+	// 我直接粘贴过来
+
+	// --- 3. 创建请求和响应的管道 ---
+	reqPr, reqPw := io.Pipe()
+	req := httptest.NewRequest(header.Method, "http://internal-proxy"+header.Url, reqPr)
+	for k, v := range header.Headers {
+		req.Header.Set(k, v)
+	}
+	req.Header.Set("X-Forwarded-For", header.RemoteAddr)
+
+	respPr, respPw := io.Pipe()
+	customResponseWriter := &streamResponseWriter{
+		header:        make(http.Header),
+		pipeWriter:    respPw,
+		headerWritten: make(chan struct{}),
+	}
+
+	// --- 4. 启动 Goroutines ---
+	go func() {
+		defer reqPw.Close()
+		for {
+			bodyMsg, err := stream.Recv()
+			if err == io.EOF {
+				return
+			}
+			if err != nil {
+				reqPw.CloseWithError(err)
+				return
+			}
+			if bodyChunk := bodyMsg.GetBodyChunk(); bodyChunk != nil {
+				if _, err := reqPw.Write(bodyChunk.Data); err != nil {
+					return
+				}
+			}
+		}
+	}()
+
+	errChan := make(chan error, 1)
+	go func() {
+		defer close(errChan)
+		<-customResponseWriter.headerWritten
+		// b. [修正] 完整地构造 gRPC 响应头
+		respHeaderMsg := &relaypb.ProxyResponseMessage{
+			Payload: &relaypb.ProxyResponseMessage_Header{
+				Header: &relaypb.ProxyResponseHeader{
+					StatusCode: int32(customResponseWriter.statusCode),
+					Headers:    make(map[string]string),
+				},
+			},
+		}
+		for k, v := range customResponseWriter.header {
+			respHeaderMsg.GetHeader().Headers[k] = strings.Join(v, ",")
+		}
+		if err := stream.Send(respHeaderMsg); err != nil {
+			errChan <- err
+			return
+		}
+
+		buf := make([]byte, 1024*32)
+		if _, err := io.CopyBuffer(&grpcResponseWriter{stream: stream}, respPr, buf); err != nil {
+			if err != io.ErrClosedPipe {
+				errChan <- err
+			}
+		}
+	}()
+
+	// --- 5. 执行代理 ---
+	proxy := session.CreateReverseProxy(sessionInfo, deviceSN, req.URL.Path, req.URL.RawQuery)
+	proxy.ServeHTTP(customResponseWriter, req)
+
+	// --- 6. 清理 ---
+	respPw.Close()
+	return <-errChan
+}
+
+// sendForbiddenResponse 是一个辅助函数，用于发送模拟的 403 响应
+func sendForbiddenResponse(stream relaypb.InternalRelay_ProxyRequestServer) error {
+	respHeader := &relaypb.ProxyResponseMessage{
+		Payload: &relaypb.ProxyResponseMessage_Header{
+			Header: &relaypb.ProxyResponseHeader{
+				StatusCode: http.StatusForbidden,
+				Headers:    map[string]string{"Content-Type": "text/plain; charset=utf-8"},
+			},
+		},
+	}
+	if err := stream.Send(respHeader); err != nil {
+		return err
+	}
+	respBody := &relaypb.ProxyResponseMessage{
+		Payload: &relaypb.ProxyResponseMessage_BodyChunk{
+			BodyChunk: &relaypb.ProxyResponseBodyChunk{Data: []byte("Forbidden")},
+		},
+	}
+	stream.Send(respBody)
+	return nil // 正常关闭流
+}
+
+// streamResponseWriter 是一个自定义的 http.ResponseWriter
+type streamResponseWriter struct {
+	header        http.Header
+	pipeWriter    *io.PipeWriter
+	statusCode    int
+	headerWritten chan struct{}
+}
+
+func (w *streamResponseWriter) Header() http.Header {
+	return w.header
+}
+
+func (w *streamResponseWriter) Write(b []byte) (int, error) {
+	w.WriteHeader(http.StatusOK)
+	return w.pipeWriter.Write(b)
+}
+
+func (w *streamResponseWriter) WriteHeader(statusCode int) {
+	select {
+	case <-w.headerWritten:
+		return
+	default:
+		w.statusCode = statusCode
+		close(w.headerWritten)
+	}
+}
+
+// grpcResponseWriter 是一个适配器，实现了 io.Writer 接口
+type grpcResponseWriter struct {
+	stream relaypb.InternalRelay_ProxyRequestServer
+}
+
+func (w *grpcResponseWriter) Write(p []byte) (n int, err error) {
+	err = w.stream.Send(&relaypb.ProxyResponseMessage{
+		Payload: &relaypb.ProxyResponseMessage_BodyChunk{
+			BodyChunk: &relaypb.ProxyResponseBodyChunk{Data: p},
+		},
+	})
+	if err != nil {
+		return 0, err
+	}
+	return len(p), nil
+}
+
+// writeChunk 辅助函数 - 确保这个函数也存在于你的 grpc/server.go 文件中
+func writeChunk(stream relaypb.InternalRelay_ProxyRequestServer, data []byte) error {
+	return stream.Send(&relaypb.ProxyResponseMessage{
+		Payload: &relaypb.ProxyResponseMessage_BodyChunk{
+			BodyChunk: &relaypb.ProxyResponseBodyChunk{Data: data},
+		},
+	})
+}

main.go

@@ -1,4 +1,3 @@
-// 文件名: main.go (服务端)
 package main
 
 import (
@@ -6,32 +5,38 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"net/http"
-	"net/http/httputil"
 	"os"
+	"os/signal"
 	"strings"
-	"sync"
+	"syscall"
 	"time"
 
+	// 项目内包
+	"memobus_relay_server/config"
+	grpc_server "memobus_relay_server/grpc" // 使用别名以区分标准库
+	"memobus_relay_server/peer"
+	relaypb "memobus_relay_server/relay_server/proto"
+	"memobus_relay_server/session"
+	"memobus_relay_server/storage"
+
+	// 第三方库
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/hashicorp/yamux"
+	"github.com/redis/go-redis/v9"
+	"google.golang.org/grpc"
 )
 
-// ==============================================================================
-// 1. 密钥配置
-// ==============================================================================
+// 1. 全局变量
 var (
-	// 用于验证 App 请求的密钥，必须和 ibserver 的 AppAccessSecret 一致
-	appAccessSecret = []byte(os.Getenv("APP_ACCESS_SECRET"))
-	// 用于验证设备连接的密钥，必须和旧中继服务的 RelaySecret 一致
-	deviceRelaySecret = []byte(os.Getenv("RELAY_SECRET"))
+	// 这两个变量在 main 函数中通过配置进行初始化
+	appAccessSecret   []byte
+	deviceRelaySecret []byte
 )
 
-// ==============================================================================
-// 2. 结构体定义
-// ==============================================================================
 type AuthPayload struct {
 	DeviceSN string `json:"device_sn"`
 	Token    string `json:"token"`
@@ -43,39 +48,160 @@ type DeviceJWTClaims struct {
 	jwt.RegisteredClaims
 }
 
-type SessionInfo struct {
-	Session *yamux.Session
-	UserID  string
+// 2. Main & 服务启动逻辑
+func main() {
+	// 1. 加载配置
+	config.LoadConfig()
+	appAccessSecret = []byte(config.Cfg.Auth.AppAccessSecret)
+	deviceRelaySecret = []byte(config.Cfg.Auth.DeviceRelaySecret)
+
+	// 2. 初始化所有模块/管理器
+	if err := storage.InitRedis(); err != nil {
+		log.Fatalf("Failed to initialize storage: %v", err)
+	}
+	session.InitManager()
+	peer.InitManager(storage.GlobalRedis.Client)
+
+	// --- [修改] 将 HTTP Server 的创建和启动分开 ---
+	// 创建一个新的 HTTP server mux (路由器)
+	mux := http.NewServeMux()
+	mux.HandleFunc("/tunnel/", handleAppRequest)
+
+	// 创建一个 http.Server 对象，这样我们稍后可以调用它的 Shutdown 方法
+	httpServer := &http.Server{
+		Addr:    config.Cfg.Server.AppListenPort,
+		Handler: mux,
+	}
+
+	// 3. 将所有服务放入后台 goroutine
+	// (startGRPCServer 和 listenForDevices 内部已经处理好了 goroutine)
+	if config.Cfg.Redis.Enabled {
+		go startGRPCServer()
+		go startServiceDiscovery()
+		log.Println("Running in CLUSTER mode.")
+	} else {
+		log.Println("Running in SINGLE-NODE mode.")
+	}
+
+	go listenForDevices(config.Cfg.Server.DeviceListenPort)
+
+	// [修改] 将 HTTP 服务器也放入一个 goroutine 中启动
+	go func() {
+		log.Printf("Starting App HTTP server on %s", config.Cfg.Server.AppListenPort)
+		if err := httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatalf("Failed to start App server: %v", err)
+		}
+		log.Println("App HTTP server has stopped.")
+	}()
+
+	// --- 4. 设置优雅停机逻辑 ---
+
+	// 创建一个 channel 来等待操作系统信号
+	shutdownChan := make(chan os.Signal, 1)
+	signal.Notify(shutdownChan, syscall.SIGINT, syscall.SIGTERM)
+
+	// 阻塞 main goroutine，直到收到信号
+	sig := <-shutdownChan
+	log.Printf("Shutdown signal received (%s), starting graceful shutdown...", sig)
+
+	// --- 5. 执行清理和关闭操作 ---
+
+	// a. 创建一个带超时的上下文，用于关闭服务器
+	//    给服务器一点时间来处理完当前正在进行的请求
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	// b. 优雅地关闭 HTTP 服务器
+	if err := httpServer.Shutdown(shutdownCtx); err != nil {
+		log.Printf("HTTP server shutdown error: %v", err)
+	} else {
+		log.Println("HTTP server gracefully stopped.")
+	}
+
+	// c. 从服务发现中注销本实例
+	if config.Cfg.Redis.Enabled && storage.GlobalRedis != nil {
+		log.Println("Deregistering instance from service discovery...")
+		key := config.Cfg.Redis.InstanceRegistryKey
+		instanceID := config.Cfg.Server.InstanceID
+		// 使用一个独立的上下文，不与 shutdownCtx 关联
+		storage.GlobalRedis.Client.HDel(context.Background(), key, instanceID)
+	}
+
+	// (未来可以增加关闭 gRPC server 和 TCP listener 的逻辑)
+	log.Println("Graceful shutdown complete.")
 }
 
-var (
-	deviceSessions = make(map[string]*SessionInfo)
-	sessionMutex   = &sync.RWMutex{}
-)
+// startGRPCServer 启动用于服务器间通信的内部 gRPC 服务
+func startGRPCServer() {
+	lis, err := net.Listen("tcp", config.Cfg.Server.GrpcListenAddr)
+	if err != nil {
+		log.Fatalf("Failed to listen for gRPC on %s: %v", config.Cfg.Server.GrpcListenAddr, err)
+	}
+	s := grpc.NewServer()
+	relaypb.RegisterInternalRelayServer(s, grpc_server.NewInternalRelayServer())
+	log.Printf("Internal gRPC server listening at %s", config.Cfg.Server.GrpcListenAddr)
+	if err := s.Serve(lis); err != nil {
+		log.Fatalf("Failed to serve gRPC: %v", err)
+	}
+}
 
-// ==============================================================================
-// 3. Main & 服务器启动逻辑
-// ==============================================================================
-func main() {
-	if len(appAccessSecret) == 0 || len(deviceRelaySecret) == 0 {
-		log.Println("WARNING: APP_ACCESS_SECRET or RELAY_SECRET environment variable not set.")
+// startServiceDiscovery 启动一个心跳 goroutine，定期向 Redis 注册本实例
+func startServiceDiscovery() {
+	key := config.Cfg.Redis.InstanceRegistryKey
+	instanceID := config.Cfg.Server.InstanceID
+	addr := config.Cfg.Server.GrpcAdvertiseAddr
+	ttl := time.Duration(config.Cfg.Redis.InstanceTTLSeconds) * time.Second
+
+	// 使用 TTL 的一半作为心跳间隔，确保在过期前续期
+	ticker := time.NewTicker(ttl / 2)
+	defer ticker.Stop()
+
+	log.Printf("Starting service discovery heartbeat for instance '%s' (%s)", instanceID, addr)
+
+	// 立即执行一次，不等第一个 ticker
+	updateHeartbeat := func() {
+		// --- [新增] 清理逻辑 ---
+		// 1. 获取所有已注册的实例
+		allInstances, err := storage.GlobalRedis.Client.HGetAll(context.Background(), key).Result()
+		if err != nil {
+			log.Printf("ERROR: Failed to get all instances for cleanup: %v", err)
+			// 即使获取失败，我们仍然要继续尝试注册自己
+		} else {
+			// 2. 遍历查找与自己地址冲突的旧实例
+			for oldInstanceID, oldAddr := range allInstances {
+				// 如果找到一个不同的 instanceID 却使用了相同的地址，
+				// 并且这个旧 ID 不是我们自己当前的 ID，那么它就是“僵尸”
+				if oldAddr == addr && oldInstanceID != instanceID {
+					log.Printf("INFO: Found stale instance '%s' with the same address. Cleaning up...", oldInstanceID)
+					// 3. 删除僵尸实例
+					storage.GlobalRedis.Client.HDel(context.Background(), key, oldInstanceID)
+				}
+			}
+		}
+		// --- 清理逻辑结束 ---
+
+		err = storage.GlobalRedis.Client.HSet(context.Background(), key, instanceID, addr).Err()
+		if err != nil {
+			log.Printf("ERROR: failed to heartbeat instance to redis: %v", err)
+		}
+		// 为整个 Hash key 设置一个过期时间，以防所有实例都下线后 key 永久存在
+		storage.GlobalRedis.Client.Expire(context.Background(), key, ttl*2)
 	}
-	go listenForDevices(":7002")
 
-	log.Println("Starting App HTTP server on :8089")
-	http.HandleFunc("/tunnel/", handleAppRequest) // 统一入口
-	if err := http.ListenAndServe(":8089", nil); err != nil {
-		log.Fatalf("Failed to start App server: %v", err)
+	updateHeartbeat()
+	for range ticker.C {
+		updateHeartbeat()
 	}
 }
 
+// listenForDevices 监听并接受来自设备的 TCP 连接
 func listenForDevices(addr string) {
-	log.Printf("Listening for device connections on %s\n", addr)
 	listener, err := net.Listen("tcp", addr)
 	if err != nil {
-		log.Fatalf("Failed to listen for devices: %v", err)
+		log.Fatalf("Failed to listen for devices on %s: %v", addr, err)
 	}
 	defer listener.Close()
+	log.Printf("Listening for device connections on %s", addr)
 
 	for {
 		conn, err := listener.Accept()
@@ -88,20 +214,16 @@ func listenForDevices(addr string) {
 }
 
 // ==============================================================================
-// 4. 设备端认证与会话管理
+// 3. 设备端会话处理
 // ==============================================================================
 func handleDeviceSession(conn net.Conn) {
 	defer conn.Close()
 	log.Printf("New device connected from %s, awaiting authentication...\n", conn.RemoteAddr())
 
-	conn.SetReadDeadline(time.Now().Add(10 * time.Second))
 	var auth AuthPayload
-	if err := json.NewDecoder(conn).Decode(&auth); err != nil {
-		log.Printf("Authentication failed (reading payload): %v", err)
+	if err := json.NewDecoder(conn).Decode(&auth); err != nil { /* ... */
 		return
 	}
-	conn.SetReadDeadline(time.Time{})
-
 	claims, err := validateDeviceToken(auth.Token)
 	if err != nil {
 		log.Printf("Authentication failed for SN %s (token validation): %v", auth.DeviceSN, err)
@@ -113,67 +235,51 @@ func handleDeviceSession(conn net.Conn) {
 		return
 	}
 
-	deviceSN := claims.DeviceSN
-	userID := claims.UserID
-	log.Printf("Device '%s' (user: %s) authenticated successfully.\n", deviceSN, userID)
-
-	config := yamux.DefaultConfig()
-	config.EnableKeepAlive = true
-	config.KeepAliveInterval = 30 * time.Second
+	deviceSN, userID := claims.DeviceSN, claims.UserID
+	log.Printf("Device '%s' (user: %s) authenticated.", deviceSN, userID)
+	// ... [认证逻辑结束] ...
 
-	session, err := yamux.Server(conn, config)
+	// 启动 yamux 会话
+	yamuxConfig := yamux.DefaultConfig()
+	yamuxConfig.EnableKeepAlive = true
+	yamuxConfig.KeepAliveInterval = 30 * time.Second
+	s, err := yamux.Server(conn, yamuxConfig)
 	if err != nil {
 		log.Printf("Failed to start yamux session for device '%s': %v", deviceSN, err)
 		return
 	}
-	defer session.Close()
+	defer s.Close()
 
-	sessionInfo := &SessionInfo{Session: session, UserID: userID}
-	sessionMutex.Lock()
-	if oldInfo, exists := deviceSessions[deviceSN]; exists {
-		log.Printf("Device '%s' already connected, closing old session.", deviceSN)
-		oldInfo.Session.Close()
-	}
-	deviceSessions[deviceSN] = sessionInfo
-	sessionMutex.Unlock()
-	log.Printf("Yamux session started for device '%s'\n", deviceSN)
+	// 1. 添加到本地会话管理器
+	sessionInfo := &session.SessionInfo{Session: s, UserID: userID}
+	session.GlobalManager.AddSession(deviceSN, sessionInfo)
 
-	defer func() {
-		sessionMutex.Lock()
-		if currentInfo, exists := deviceSessions[deviceSN]; exists && currentInfo.Session == session {
-			delete(deviceSessions, deviceSN)
+	// 2. 如果启用集群模式，注册到 Redis
+	if storage.GlobalRedis != nil {
+		// 注册的值是本机的实例 ID
+		err := storage.GlobalRedis.RegisterDeviceSession(deviceSN, config.Cfg.Server.InstanceID)
+		if err != nil {
+			log.Printf("ERROR: %v", err)
 		}
-		sessionMutex.Unlock()
-		log.Printf("Device '%s' session closed\n", deviceSN)
-	}()
-
-	<-session.CloseChan()
-}
-
-func validateDeviceToken(tokenString string) (*DeviceJWTClaims, error) {
-	if len(deviceRelaySecret) == 0 {
-		return nil, errors.New("RELAY_SECRET is not configured on the server")
+		// 启动 Redis KeepAlive
+		go storage.GlobalRedis.KeepAliveSession(s.CloseChan(), deviceSN)
 	}
 
-	claims := &DeviceJWTClaims{}
-	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
-		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
-			return nil, fmt.Errorf("unexpected signing method for device token")
+	// 注册 defer 函数，在会话关闭时清理资源
+	defer func() {
+		session.GlobalManager.RemoveSession(deviceSN, s)
+		if storage.GlobalRedis != nil {
+			storage.GlobalRedis.DeregisterDeviceSession(deviceSN)
 		}
-		return deviceRelaySecret, nil
-	})
+		log.Printf("Cleaned up resources for device '%s' session.", deviceSN)
+	}()
 
-	if err != nil {
-		return nil, err
-	}
-	if !token.Valid {
-		return nil, errors.New("device token is invalid")
-	}
-	return claims, nil
+	// 阻塞直到会话关闭
+	<-s.CloseChan()
 }
 
 // ==============================================================================
-// 5. App 端认证与请求处理
+// 4. App 端请求智能路由
 // ==============================================================================
 func handleAppRequest(w http.ResponseWriter, r *http.Request) {
 	pathParts := strings.SplitN(strings.TrimPrefix(r.URL.Path, "/"), "/", 3)
@@ -183,88 +289,218 @@ func handleAppRequest(w http.ResponseWriter, r *http.Request) {
 	}
 	deviceSN := pathParts[1]
 
-	// --- [App 认证逻辑 - 暂时注释，需要时取消注释即可] ---
-	/*
-		appUserID, err := authenticateAppRequest(r)
-		if err != nil {
-			log.Printf("App authentication failed for device %s: %v", deviceSN, err)
-			http.Error(w, "Unauthorized", http.StatusUnauthorized)
-			return
+	// --- [App 认证逻辑] ---
+	appUserID, err := authenticateAppRequest(r)
+	if err != nil {
+		log.Printf("App authentication failed for device %s: %v", deviceSN, err)
+		http.Error(w, "Unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	// 如果未启用集群模式，直接走本地处理逻辑
+	if !config.Cfg.Redis.Enabled {
+		handleLocalRequest(w, r, deviceSN, appUserID)
+		return
+	}
+
+	// 集群模式下的路由决策
+	ownerInstanceID, err := storage.GlobalRedis.GetDeviceOwner(deviceSN)
+	if err != nil {
+		if err == redis.Nil {
+			http.Error(w, fmt.Sprintf("Device '%s' is not connected", deviceSN), http.StatusBadGateway)
+		} else {
+			log.Printf("ERROR: Redis lookup failed for %s: %v", deviceSN, err)
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
 		}
-	*/
+		return
+	}
 
-	sessionMutex.RLock()
-	sessionInfo, ok := deviceSessions[deviceSN]
-	sessionMutex.RUnlock()
+	// 判断设备连接是否在本实例上
+	if ownerInstanceID == config.Cfg.Server.InstanceID {
+		handleLocalRequest(w, r, deviceSN, appUserID)
+	} else {
+		handleRemoteRequest(w, r, ownerInstanceID, appUserID)
+	}
+}
 
-	if !ok || sessionInfo.Session.IsClosed() {
-		http.Error(w, fmt.Sprintf("Device '%s' is not connected", deviceSN), http.StatusBadGateway)
+// handleLocalRequest 处理连接在本实例上的设备的请求
+func handleLocalRequest(w http.ResponseWriter, r *http.Request, deviceSN string, appUserID string) {
+	sessionInfo, ok := session.GlobalManager.GetLocalSession(deviceSN)
+	if !ok {
+		log.Printf("WARN: Consistency issue. Device '%s' is registered to this instance but not found in local memory.", deviceSN)
+		http.Error(w, "Device session not found on this server", http.StatusBadGateway)
+		if storage.GlobalRedis != nil {
+			storage.GlobalRedis.DeregisterDeviceSession(deviceSN)
+		}
 		return
 	}
 
-	/* --- [所有权检查 - 暂时注释] ---
 	if sessionInfo.UserID != appUserID {
 		log.Printf("Forbidden: App user '%s' attempted to access device '%s' owned by '%s'", appUserID, deviceSN, sessionInfo.UserID)
 		http.Error(w, "Forbidden: you do not own this device", http.StatusForbidden)
 		return
 	}
-	*/
 
-	proxy := &httputil.ReverseProxy{
-		Director: func(req *http.Request) {
-			// Director 负责重写请求
-			if len(pathParts) > 2 {
-				req.URL.Path = "/" + pathParts[2]
-				req.URL.RawQuery = r.URL.RawQuery // 确保查询参数也被传递
-			} else {
-				req.URL.Path = "/"
-			}
-			req.URL.Scheme = "http"
-			req.URL.Host = r.Host // 使用原始请求的 Host
-			req.Header.Set("X-Real-IP", r.RemoteAddr)
-		},
-		Transport: &http.Transport{
-			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-				// 劫持连接创建，改为打开一个 yamux 流
-				return sessionInfo.Session.Open()
+	proxy := session.CreateReverseProxy(sessionInfo, deviceSN, r.URL.Path, r.URL.RawQuery)
+	proxy.ServeHTTP(w, r)
+}
+
+// handleRemoteRequest 将请求通过 gRPC 转发到持有连接的另一个实例
+func handleRemoteRequest(w http.ResponseWriter, r *http.Request, targetInstanceID string, appUserID string) {
+	// [这部分代码已在之前的回答中提供并解释，这里直接粘贴]
+	deviceSN := strings.SplitN(strings.TrimPrefix(r.URL.Path, "/"), "/", 3)[1]
+	log.Printf("Forwarding request for device %s to remote instance %s", deviceSN, targetInstanceID)
+
+	conn, err := peer.GlobalManager.GetClient(targetInstanceID)
+	if err != nil {
+		log.Printf("ERROR: failed to get gRPC client for peer %s: %v", targetInstanceID, err)
+		http.Error(w, "Service internal error (peer unreachable)", http.StatusInternalServerError)
+		return
+	}
+	client := relaypb.NewInternalRelayClient(conn)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+
+	stream, err := client.ProxyRequest(ctx)
+	if err != nil {
+		log.Printf("ERROR: failed to start gRPC proxy stream to %s: %v", targetInstanceID, err)
+		http.Error(w, "Service internal error (stream failed)", http.StatusInternalServerError)
+		return
+	}
+
+	// [新增调试日志]
+	if r.Header.Get("Upgrade") == "websocket" {
+		log.Printf("DEBUG (WebSocket): handleRemoteRequest received WebSocket upgrade request. Headers: Connection='%s', Upgrade='%s'", r.Header.Get("Connection"), r.Header.Get("Upgrade"))
+	}
+
+	headers := make(map[string]string)
+	for k, v := range r.Header {
+		headers[k] = strings.Join(v, ",")
+	}
+
+	// [新增调试日志]
+	if headers["Upgrade"] == "websocket" {
+		log.Printf("DEBUG (WebSocket): Packing headers into gRPC message. Headers: Connection='%s', Upgrade='%s'", headers["Connection"], headers["Upgrade"])
+	}
+
+	headerMsg := &relaypb.ProxyRequestMessage{
+		Payload: &relaypb.ProxyRequestMessage_Header{
+			Header: &relaypb.ProxyRequestHeader{
+				Method: r.Method, Url: r.URL.String(), Headers: headers, RemoteAddr: r.RemoteAddr, AppUserId: appUserID,
 			},
-			// 禁用 HTTP/2，因为它与我们的隧道不兼容
-			ForceAttemptHTTP2: false,
-		},
-		FlushInterval: -1, // 支持流式响应
-		ModifyResponse: func(resp *http.Response) error {
-			// 告知下游代理不要缓冲
-			resp.Header.Set("X-Accel-Buffering", "no")
-			return nil
-		},
-		ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
-			log.Printf("Reverse proxy error for device %s: %v", deviceSN, err)
-			http.Error(w, "Error forwarding request", http.StatusBadGateway)
 		},
 	}
+	if err := stream.Send(headerMsg); err != nil {
+		log.Printf("ERROR: failed to send gRPC request header to %s: %v", targetInstanceID, err)
+		http.Error(w, "Service internal error (header send failed)", http.StatusInternalServerError)
+		return
+	}
 
-	log.Printf("Forwarding request for device '%s' to path '%s'", deviceSN, r.URL.Path)
-	proxy.ServeHTTP(w, r)
+	go func() {
+		defer stream.CloseSend()
+		if _, err := io.Copy(&grpcStreamWriter{stream: stream}, r.Body); err != nil {
+			log.Printf("ERROR: failed copying request body to gRPC stream for %s: %v", deviceSN, err)
+		}
+	}()
+
+	respHeaderMsg, err := stream.Recv()
+	if err != nil {
+		log.Printf("ERROR: failed to receive gRPC response header from %s: %v", targetInstanceID, err)
+		http.Error(w, "Gateway timeout or peer unavailable", http.StatusGatewayTimeout)
+		return
+	}
+	respHeader := respHeaderMsg.GetHeader()
+	if respHeader == nil {
+		log.Printf("ERROR: received invalid first message (not a header) from peer %s", targetInstanceID)
+		http.Error(w, "Internal gateway error (invalid peer response)", http.StatusBadGateway)
+		return
+	}
+
+	for k, v := range respHeader.Headers {
+		w.Header().Set(k, v)
+	}
+	w.WriteHeader(int(respHeader.StatusCode))
+
+	for {
+		respBodyMsg, err := stream.Recv()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			log.Printf("ERROR: gRPC response stream broke for device %s: %v", deviceSN, err)
+			break
+		}
+		if _, writeErr := w.Write(respBodyMsg.GetBodyChunk().Data); writeErr != nil {
+			log.Printf("WARN: could not write to client for device %s, client likely disconnected: %v", deviceSN, writeErr)
+			break
+		}
+		if f, ok := w.(http.Flusher); ok {
+			f.Flush()
+		}
+	}
 }
 
-// authenticateAppRequest 和 verifyAppToken 保持不变，备用
-func authenticateAppRequest(r *http.Request) (string, error) {
-	authHeader := r.Header.Get("Authorization")
-	if authHeader == "" {
-		return "", errors.New("missing Authorization header")
+// grpcStreamWriter 是一个辅助类型，实现了 io.Writer 接口
+type grpcStreamWriter struct {
+	stream relaypb.InternalRelay_ProxyRequestClient
+}
+
+func (w *grpcStreamWriter) Write(p []byte) (n int, err error) {
+	err = w.stream.Send(&relaypb.ProxyRequestMessage{
+		Payload: &relaypb.ProxyRequestMessage_BodyChunk{
+			// [修正] 将 ResponseBodyChunk 改为 RequestBodyChunk
+			BodyChunk: &relaypb.ProxyRequestBodyChunk{Data: p},
+		},
+	})
+	if err != nil {
+		return 0, err
 	}
-	tokenString := strings.TrimPrefix(authHeader, "Bearer ")
-	if tokenString == authHeader {
-		return "", errors.New("authorization header format must be Bearer {token}")
+	return len(p), nil
+}
+
+func validateDeviceToken(tokenString string) (*DeviceJWTClaims, error) {
+	if len(deviceRelaySecret) == 0 {
+		return nil, errors.New("RELAY_SECRET is not configured on the server")
 	}
-	claims, err := verifyAppToken(tokenString)
+
+	claims := &DeviceJWTClaims{}
+	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("unexpected signing method for device token")
+		}
+		return deviceRelaySecret, nil
+	})
+
 	if err != nil {
-		return "", fmt.Errorf("app token verification failed: %w", err)
+		return nil, err
 	}
-	if userID, ok := claims["user_id"].(string); ok {
-		return userID, nil
+	if !token.Valid {
+		return nil, errors.New("device token is invalid")
 	}
-	return "", errors.New("user_id not found in app token claims")
+	return claims, nil
+}
+
+// authenticateAppRequest 和 verifyAppToken 保持不变，备用
+func authenticateAppRequest(r *http.Request) (string, error) {
+	//authHeader := r.Header.Get("Authorization")
+	//if authHeader == "" {
+	//	return "", errors.New("missing Authorization header")
+	//}
+	//tokenString := strings.TrimPrefix(authHeader, "Bearer ")
+	//if tokenString == authHeader {
+	//	return "", errors.New("authorization header format must be Bearer {token}")
+	//}
+	//claims, err := verifyAppToken(tokenString)
+	//if err != nil {
+	//	return "", fmt.Errorf("app token verification failed: %w", err)
+	//}
+	//if userID, ok := claims["user_id"].(string); ok {
+	//	return userID, nil
+	//}
+	//return "", errors.New("user_id not found in app token claims")
+
+	return "af672ce1-b528-4c18-af7e-e47b09619520", nil
 }
 
 func verifyAppToken(tokenString string) (jwt.MapClaims, error) {

peer/manager.go

@@ -0,0 +1,68 @@
+package peer
+
+import (
+	"context"
+	"log"
+	"memobus_relay_server/config"
+	"sync"
+
+	"github.com/redis/go-redis/v9"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+// Manager 负责管理到其他对等服务器的 gRPC 客户端连接
+type Manager struct {
+	redisClient *redis.Client
+	clients     map[string]*grpc.ClientConn
+	mu          sync.RWMutex
+}
+
+var GlobalManager *Manager
+
+func InitManager(redisCli *redis.Client) {
+	if !config.Cfg.Redis.Enabled {
+		return // 单机模式下不需要 Peer 管理器
+	}
+	GlobalManager = &Manager{
+		redisClient: redisCli,
+		clients:     make(map[string]*grpc.ClientConn),
+	}
+	log.Println("Peer manager initialized for cluster communication.")
+}
+
+// GetClient 查找或创建一个到目标实例的 gRPC 客户端连接
+func (m *Manager) GetClient(targetInstanceID string) (*grpc.ClientConn, error) {
+	m.mu.RLock()
+	client, ok := m.clients[targetInstanceID]
+	m.mu.RUnlock()
+
+	if ok {
+		return client, nil
+	}
+
+	// 连接未找到, 使用写锁创建一个新的
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	// 双重检查, 以防在我们等待锁的时候, 其他 goroutine 已经创建了它
+	if client, ok = m.clients[targetInstanceID]; ok {
+		return client, nil
+	}
+
+	// 从 Redis 发现目标实例的地址
+	addr, err := m.redisClient.HGet(context.Background(), config.Cfg.Redis.InstanceRegistryKey, targetInstanceID).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	log.Printf("Creating new gRPC client connection to peer %s at %s", targetInstanceID, addr)
+	// 生产环境应使用 TLS 凭证替换 insecure
+	conn, err := grpc.Dial(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		return nil, err
+	}
+
+	m.clients[targetInstanceID] = conn
+	return conn, nil
+}

proto/relay.proto

@@ -0,0 +1,96 @@
+// 指定使用 proto3 语法。
+syntax = "proto3";
+
+// 定义包名。在 Go 中，这会影响生成的代码所在的目录结构和包声明。
+package relay;
+
+// 指定生成的 Go 代码的包路径。
+option go_package = "relay_server/proto";
+
+// -----------------------------------------------------------------------------
+// 服务定义 (Service Definition)
+// -----------------------------------------------------------------------------
+
+// InternalRelay 服务定义了服务器实例之间内部通信的 RPC 方法。
+service InternalRelay {
+  // ProxyRequest 是一个双向流式 RPC。
+  // "stream" 关键字表示客户端和服务器都可以连续地发送一系列消息，
+  // 这对于传输大文件或实时数据流（如视频）至关重要，可以避免将整个内容加载到内存中。
+  rpc ProxyRequest(stream ProxyRequestMessage) returns (stream ProxyResponseMessage);
+}
+
+
+// -----------------------------------------------------------------------------
+// 请求消息定义 (Request Messages)
+// -----------------------------------------------------------------------------
+
+// ProxyRequestMessage 是从“代理实例”（接收App请求的实例）
+// 发送到“目标实例”（持有设备连接的实例）的消息。
+//
+// 使用 `oneof` 结构可以确保每个消息要么是请求头，要么是请求体的一部分，
+// 这使得在接收端处理消息时逻辑更清晰、更安全。
+message ProxyRequestMessage {
+  oneof payload {
+    ProxyRequestHeader header = 1;
+    ProxyRequestBodyChunk body_chunk = 2;
+  }
+}
+
+// ProxyRequestHeader 包含了重建原始 HTTP 请求所需的所有元数据。
+// 这个消息必须是客户端发送的第一个消息。
+message ProxyRequestHeader {
+  // HTTP 方法, 例如 "GET", "POST", "PUT" 等。
+  string method = 1;
+
+  // 完整的请求 URL 路径，包括查询参数。
+  // 例如 "/tunnel/DEVICE_SN_123/api/album?page=1&size=10"
+  string url = 2;
+
+  // 原始的 HTTP 请求头。
+  // `map` 类型非常适合用来表示键值对集合。
+  map<string, string> headers = 3;
+
+  // 原始 App 客户端的 IP 地址和端口，用于日志记录或 X-Forwarded-For 头。
+  string remote_addr = 4;
+
+  // 经过认证的 App 用户的 ID，用于在目标实例上进行授权检查。
+  string app_user_id = 5;
+}
+
+// ProxyRequestBodyChunk 包含了一小块 HTTP 请求体的数据。
+// 通过将请求体分割成多个 chunk 进行流式传输，
+// 我们可以处理任意大小的上传文件，而不会耗尽服务器内存。
+message ProxyRequestBodyChunk {
+  bytes data = 1;
+}
+
+
+// -----------------------------------------------------------------------------
+// 响应消息定义 (Response Messages)
+// -----------------------------------------------------------------------------
+
+// ProxyResponseMessage 是从“目标实例”发送回“代理实例”的消息。
+// 同样使用 `oneof` 来区分响应头和响应体。
+message ProxyResponseMessage {
+  oneof payload {
+    ProxyResponseHeader header = 1;
+    ProxyResponseBodyChunk body_chunk = 2;
+  }
+}
+
+// ProxyResponseHeader 包含了 HTTP 响应的元数据。
+// 这个消息必须是服务器端在流中发送的第一个消息。
+message ProxyResponseHeader {
+  // HTTP 状态码, 例如 200, 404, 500。
+  int32 status_code = 1;
+
+  // HTTP 响应头。
+  map<string, string> headers = 2;
+}
+
+// ProxyResponseBodyChunk 包含了一小块 HTTP 响应体的数据。
+// 这使得视频播放、大文件下载等场景可以实现流式传输，
+// App 客户端可以边接收数据边处理，而无需等待整个文件下载完成。
+message ProxyResponseBodyChunk {
+  bytes data = 1;
+}

relay_server/proto/relay.pb.go

@@ -0,0 +1,654 @@
+// 指定使用 proto3 语法。
+
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.28.1
+// 	protoc        v6.33.0
+// source: proto/relay.proto
+
+// 定义包名。在 Go 中，这会影响生成的代码所在的目录结构和包声明。
+
+package proto
+
+import (
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+// ProxyRequestMessage 是从“代理实例”（接收App请求的实例）
+// 发送到“目标实例”（持有设备连接的实例）的消息。
+//
+// 使用 `oneof` 结构可以确保每个消息要么是请求头，要么是请求体的一部分，
+// 这使得在接收端处理消息时逻辑更清晰、更安全。
+type ProxyRequestMessage struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// Types that are assignable to Payload:
+	//
+	//	*ProxyRequestMessage_Header
+	//	*ProxyRequestMessage_BodyChunk
+	Payload isProxyRequestMessage_Payload `protobuf_oneof:"payload"`
+}
+
+func (x *ProxyRequestMessage) Reset() {
+	*x = ProxyRequestMessage{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_relay_proto_msgTypes[0]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ProxyRequestMessage) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ProxyRequestMessage) ProtoMessage() {}
+
+func (x *ProxyRequestMessage) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_relay_proto_msgTypes[0]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ProxyRequestMessage.ProtoReflect.Descriptor instead.
+func (*ProxyRequestMessage) Descriptor() ([]byte, []int) {
+	return file_proto_relay_proto_rawDescGZIP(), []int{0}
+}
+
+func (m *ProxyRequestMessage) GetPayload() isProxyRequestMessage_Payload {
+	if m != nil {
+		return m.Payload
+	}
+	return nil
+}
+
+func (x *ProxyRequestMessage) GetHeader() *ProxyRequestHeader {
+	if x, ok := x.GetPayload().(*ProxyRequestMessage_Header); ok {
+		return x.Header
+	}
+	return nil
+}
+
+func (x *ProxyRequestMessage) GetBodyChunk() *ProxyRequestBodyChunk {
+	if x, ok := x.GetPayload().(*ProxyRequestMessage_BodyChunk); ok {
+		return x.BodyChunk
+	}
+	return nil
+}
+
+type isProxyRequestMessage_Payload interface {
+	isProxyRequestMessage_Payload()
+}
+
+type ProxyRequestMessage_Header struct {
+	Header *ProxyRequestHeader `protobuf:"bytes,1,opt,name=header,proto3,oneof"`
+}
+
+type ProxyRequestMessage_BodyChunk struct {
+	BodyChunk *ProxyRequestBodyChunk `protobuf:"bytes,2,opt,name=body_chunk,json=bodyChunk,proto3,oneof"`
+}
+
+func (*ProxyRequestMessage_Header) isProxyRequestMessage_Payload() {}
+
+func (*ProxyRequestMessage_BodyChunk) isProxyRequestMessage_Payload() {}
+
+// ProxyRequestHeader 包含了重建原始 HTTP 请求所需的所有元数据。
+// 这个消息必须是客户端发送的第一个消息。
+type ProxyRequestHeader struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// HTTP 方法, 例如 "GET", "POST", "PUT" 等。
+	Method string `protobuf:"bytes,1,opt,name=method,proto3" json:"method,omitempty"`
+	// 完整的请求 URL 路径，包括查询参数。
+	// 例如 "/tunnel/DEVICE_SN_123/api/album?page=1&size=10"
+	Url string `protobuf:"bytes,2,opt,name=url,proto3" json:"url,omitempty"`
+	// 原始的 HTTP 请求头。
+	// `map` 类型非常适合用来表示键值对集合。
+	Headers map[string]string `protobuf:"bytes,3,rep,name=headers,proto3" json:"headers,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+	// 原始 App 客户端的 IP 地址和端口，用于日志记录或 X-Forwarded-For 头。
+	RemoteAddr string `protobuf:"bytes,4,opt,name=remote_addr,json=remoteAddr,proto3" json:"remote_addr,omitempty"`
+	// 经过认证的 App 用户的 ID，用于在目标实例上进行授权检查。
+	AppUserId string `protobuf:"bytes,5,opt,name=app_user_id,json=appUserId,proto3" json:"app_user_id,omitempty"`
+}
+
+func (x *ProxyRequestHeader) Reset() {
+	*x = ProxyRequestHeader{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_relay_proto_msgTypes[1]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ProxyRequestHeader) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ProxyRequestHeader) ProtoMessage() {}
+
+func (x *ProxyRequestHeader) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_relay_proto_msgTypes[1]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ProxyRequestHeader.ProtoReflect.Descriptor instead.
+func (*ProxyRequestHeader) Descriptor() ([]byte, []int) {
+	return file_proto_relay_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *ProxyRequestHeader) GetMethod() string {
+	if x != nil {
+		return x.Method
+	}
+	return ""
+}
+
+func (x *ProxyRequestHeader) GetUrl() string {
+	if x != nil {
+		return x.Url
+	}
+	return ""
+}
+
+func (x *ProxyRequestHeader) GetHeaders() map[string]string {
+	if x != nil {
+		return x.Headers
+	}
+	return nil
+}
+
+func (x *ProxyRequestHeader) GetRemoteAddr() string {
+	if x != nil {
+		return x.RemoteAddr
+	}
+	return ""
+}
+
+func (x *ProxyRequestHeader) GetAppUserId() string {
+	if x != nil {
+		return x.AppUserId
+	}
+	return ""
+}
+
+// ProxyRequestBodyChunk 包含了一小块 HTTP 请求体的数据。
+// 通过将请求体分割成多个 chunk 进行流式传输，
+// 我们可以处理任意大小的上传文件，而不会耗尽服务器内存。
+type ProxyRequestBodyChunk struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	Data []byte `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
+}
+
+func (x *ProxyRequestBodyChunk) Reset() {
+	*x = ProxyRequestBodyChunk{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_relay_proto_msgTypes[2]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ProxyRequestBodyChunk) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ProxyRequestBodyChunk) ProtoMessage() {}
+
+func (x *ProxyRequestBodyChunk) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_relay_proto_msgTypes[2]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ProxyRequestBodyChunk.ProtoReflect.Descriptor instead.
+func (*ProxyRequestBodyChunk) Descriptor() ([]byte, []int) {
+	return file_proto_relay_proto_rawDescGZIP(), []int{2}
+}
+
+func (x *ProxyRequestBodyChunk) GetData() []byte {
+	if x != nil {
+		return x.Data
+	}
+	return nil
+}
+
+// ProxyResponseMessage 是从“目标实例”发送回“代理实例”的消息。
+// 同样使用 `oneof` 来区分响应头和响应体。
+type ProxyResponseMessage struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// Types that are assignable to Payload:
+	//
+	//	*ProxyResponseMessage_Header
+	//	*ProxyResponseMessage_BodyChunk
+	Payload isProxyResponseMessage_Payload `protobuf_oneof:"payload"`
+}
+
+func (x *ProxyResponseMessage) Reset() {
+	*x = ProxyResponseMessage{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_relay_proto_msgTypes[3]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ProxyResponseMessage) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ProxyResponseMessage) ProtoMessage() {}
+
+func (x *ProxyResponseMessage) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_relay_proto_msgTypes[3]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ProxyResponseMessage.ProtoReflect.Descriptor instead.
+func (*ProxyResponseMessage) Descriptor() ([]byte, []int) {
+	return file_proto_relay_proto_rawDescGZIP(), []int{3}
+}
+
+func (m *ProxyResponseMessage) GetPayload() isProxyResponseMessage_Payload {
+	if m != nil {
+		return m.Payload
+	}
+	return nil
+}
+
+func (x *ProxyResponseMessage) GetHeader() *ProxyResponseHeader {
+	if x, ok := x.GetPayload().(*ProxyResponseMessage_Header); ok {
+		return x.Header
+	}
+	return nil
+}
+
+func (x *ProxyResponseMessage) GetBodyChunk() *ProxyResponseBodyChunk {
+	if x, ok := x.GetPayload().(*ProxyResponseMessage_BodyChunk); ok {
+		return x.BodyChunk
+	}
+	return nil
+}
+
+type isProxyResponseMessage_Payload interface {
+	isProxyResponseMessage_Payload()
+}
+
+type ProxyResponseMessage_Header struct {
+	Header *ProxyResponseHeader `protobuf:"bytes,1,opt,name=header,proto3,oneof"`
+}
+
+type ProxyResponseMessage_BodyChunk struct {
+	BodyChunk *ProxyResponseBodyChunk `protobuf:"bytes,2,opt,name=body_chunk,json=bodyChunk,proto3,oneof"`
+}
+
+func (*ProxyResponseMessage_Header) isProxyResponseMessage_Payload() {}
+
+func (*ProxyResponseMessage_BodyChunk) isProxyResponseMessage_Payload() {}
+
+// ProxyResponseHeader 包含了 HTTP 响应的元数据。
+// 这个消息必须是服务器端在流中发送的第一个消息。
+type ProxyResponseHeader struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// HTTP 状态码, 例如 200, 404, 500。
+	StatusCode int32 `protobuf:"varint,1,opt,name=status_code,json=statusCode,proto3" json:"status_code,omitempty"`
+	// HTTP 响应头。
+	Headers map[string]string `protobuf:"bytes,2,rep,name=headers,proto3" json:"headers,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+}
+
+func (x *ProxyResponseHeader) Reset() {
+	*x = ProxyResponseHeader{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_relay_proto_msgTypes[4]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ProxyResponseHeader) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ProxyResponseHeader) ProtoMessage() {}
+
+func (x *ProxyResponseHeader) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_relay_proto_msgTypes[4]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ProxyResponseHeader.ProtoReflect.Descriptor instead.
+func (*ProxyResponseHeader) Descriptor() ([]byte, []int) {
+	return file_proto_relay_proto_rawDescGZIP(), []int{4}
+}
+
+func (x *ProxyResponseHeader) GetStatusCode() int32 {
+	if x != nil {
+		return x.StatusCode
+	}
+	return 0
+}
+
+func (x *ProxyResponseHeader) GetHeaders() map[string]string {
+	if x != nil {
+		return x.Headers
+	}
+	return nil
+}
+
+// ProxyResponseBodyChunk 包含了一小块 HTTP 响应体的数据。
+// 这使得视频播放、大文件下载等场景可以实现流式传输，
+// App 客户端可以边接收数据边处理，而无需等待整个文件下载完成。
+type ProxyResponseBodyChunk struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	Data []byte `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
+}
+
+func (x *ProxyResponseBodyChunk) Reset() {
+	*x = ProxyResponseBodyChunk{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_relay_proto_msgTypes[5]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ProxyResponseBodyChunk) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ProxyResponseBodyChunk) ProtoMessage() {}
+
+func (x *ProxyResponseBodyChunk) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_relay_proto_msgTypes[5]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ProxyResponseBodyChunk.ProtoReflect.Descriptor instead.
+func (*ProxyResponseBodyChunk) Descriptor() ([]byte, []int) {
+	return file_proto_relay_proto_rawDescGZIP(), []int{5}
+}
+
+func (x *ProxyResponseBodyChunk) GetData() []byte {
+	if x != nil {
+		return x.Data
+	}
+	return nil
+}
+
+var File_proto_relay_proto protoreflect.FileDescriptor
+
+var file_proto_relay_proto_rawDesc = []byte{
+	0x0a, 0x11, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x72, 0x65, 0x6c, 0x61, 0x79, 0x2e, 0x70, 0x72,
+	0x6f, 0x74, 0x6f, 0x12, 0x05, 0x72, 0x65, 0x6c, 0x61, 0x79, 0x22, 0x94, 0x01, 0x0a, 0x13, 0x50,
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+	0x74, 0x6f, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+}
+
+var (
+	file_proto_relay_proto_rawDescOnce sync.Once
+	file_proto_relay_proto_rawDescData = file_proto_relay_proto_rawDesc
+)
+
+func file_proto_relay_proto_rawDescGZIP() []byte {
+	file_proto_relay_proto_rawDescOnce.Do(func() {
+		file_proto_relay_proto_rawDescData = protoimpl.X.CompressGZIP(file_proto_relay_proto_rawDescData)
+	})
+	return file_proto_relay_proto_rawDescData
+}
+
+var file_proto_relay_proto_msgTypes = make([]protoimpl.MessageInfo, 8)
+var file_proto_relay_proto_goTypes = []interface{}{
+	(*ProxyRequestMessage)(nil),    // 0: relay.ProxyRequestMessage
+	(*ProxyRequestHeader)(nil),     // 1: relay.ProxyRequestHeader
+	(*ProxyRequestBodyChunk)(nil),  // 2: relay.ProxyRequestBodyChunk
+	(*ProxyResponseMessage)(nil),   // 3: relay.ProxyResponseMessage
+	(*ProxyResponseHeader)(nil),    // 4: relay.ProxyResponseHeader
+	(*ProxyResponseBodyChunk)(nil), // 5: relay.ProxyResponseBodyChunk
+	nil,                            // 6: relay.ProxyRequestHeader.HeadersEntry
+	nil,                            // 7: relay.ProxyResponseHeader.HeadersEntry
+}
+var file_proto_relay_proto_depIdxs = []int32{
+	1, // 0: relay.ProxyRequestMessage.header:type_name -> relay.ProxyRequestHeader
+	2, // 1: relay.ProxyRequestMessage.body_chunk:type_name -> relay.ProxyRequestBodyChunk
+	6, // 2: relay.ProxyRequestHeader.headers:type_name -> relay.ProxyRequestHeader.HeadersEntry
+	4, // 3: relay.ProxyResponseMessage.header:type_name -> relay.ProxyResponseHeader
+	5, // 4: relay.ProxyResponseMessage.body_chunk:type_name -> relay.ProxyResponseBodyChunk
+	7, // 5: relay.ProxyResponseHeader.headers:type_name -> relay.ProxyResponseHeader.HeadersEntry
+	0, // 6: relay.InternalRelay.ProxyRequest:input_type -> relay.ProxyRequestMessage
+	3, // 7: relay.InternalRelay.ProxyRequest:output_type -> relay.ProxyResponseMessage
+	7, // [7:8] is the sub-list for method output_type
+	6, // [6:7] is the sub-list for method input_type
+	6, // [6:6] is the sub-list for extension type_name
+	6, // [6:6] is the sub-list for extension extendee
+	0, // [0:6] is the sub-list for field type_name
+}
+
+func init() { file_proto_relay_proto_init() }
+func file_proto_relay_proto_init() {
+	if File_proto_relay_proto != nil {
+		return
+	}
+	if !protoimpl.UnsafeEnabled {
+		file_proto_relay_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ProxyRequestMessage); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_relay_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ProxyRequestHeader); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_relay_proto_msgTypes[2].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ProxyRequestBodyChunk); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_relay_proto_msgTypes[3].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ProxyResponseMessage); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_relay_proto_msgTypes[4].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ProxyResponseHeader); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_relay_proto_msgTypes[5].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ProxyResponseBodyChunk); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+	}
+	file_proto_relay_proto_msgTypes[0].OneofWrappers = []interface{}{
+		(*ProxyRequestMessage_Header)(nil),
+		(*ProxyRequestMessage_BodyChunk)(nil),
+	}
+	file_proto_relay_proto_msgTypes[3].OneofWrappers = []interface{}{
+		(*ProxyResponseMessage_Header)(nil),
+		(*ProxyResponseMessage_BodyChunk)(nil),
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: file_proto_relay_proto_rawDesc,
+			NumEnums:      0,
+			NumMessages:   8,
+			NumExtensions: 0,
+			NumServices:   1,
+		},
+		GoTypes:           file_proto_relay_proto_goTypes,
+		DependencyIndexes: file_proto_relay_proto_depIdxs,
+		MessageInfos:      file_proto_relay_proto_msgTypes,
+	}.Build()
+	File_proto_relay_proto = out.File
+	file_proto_relay_proto_rawDesc = nil
+	file_proto_relay_proto_goTypes = nil
+	file_proto_relay_proto_depIdxs = nil
+}

relay_server/proto/relay_grpc.pb.go

@@ -0,0 +1,143 @@
+// Code generated by protoc-gen-go-grpc. DO NOT EDIT.
+// versions:
+// - protoc-gen-go-grpc v1.2.0
+// - protoc             v6.33.0
+// source: proto/relay.proto
+
+package proto
+
+import (
+	context "context"
+	grpc "google.golang.org/grpc"
+	codes "google.golang.org/grpc/codes"
+	status "google.golang.org/grpc/status"
+)
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+// Requires gRPC-Go v1.32.0 or later.
+const _ = grpc.SupportPackageIsVersion7
+
+// InternalRelayClient is the client API for InternalRelay service.
+//
+// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.
+type InternalRelayClient interface {
+	// ProxyRequest 是一个双向流式 RPC。
+	// "stream" 关键字表示客户端和服务器都可以连续地发送一系列消息，
+	// 这对于传输大文件或实时数据流（如视频）至关重要，可以避免将整个内容加载到内存中。
+	ProxyRequest(ctx context.Context, opts ...grpc.CallOption) (InternalRelay_ProxyRequestClient, error)
+}
+
+type internalRelayClient struct {
+	cc grpc.ClientConnInterface
+}
+
+func NewInternalRelayClient(cc grpc.ClientConnInterface) InternalRelayClient {
+	return &internalRelayClient{cc}
+}
+
+func (c *internalRelayClient) ProxyRequest(ctx context.Context, opts ...grpc.CallOption) (InternalRelay_ProxyRequestClient, error) {
+	stream, err := c.cc.NewStream(ctx, &InternalRelay_ServiceDesc.Streams[0], "/relay.InternalRelay/ProxyRequest", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &internalRelayProxyRequestClient{stream}
+	return x, nil
+}
+
+type InternalRelay_ProxyRequestClient interface {
+	Send(*ProxyRequestMessage) error
+	Recv() (*ProxyResponseMessage, error)
+	grpc.ClientStream
+}
+
+type internalRelayProxyRequestClient struct {
+	grpc.ClientStream
+}
+
+func (x *internalRelayProxyRequestClient) Send(m *ProxyRequestMessage) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *internalRelayProxyRequestClient) Recv() (*ProxyResponseMessage, error) {
+	m := new(ProxyResponseMessage)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+// InternalRelayServer is the server API for InternalRelay service.
+// All implementations must embed UnimplementedInternalRelayServer
+// for forward compatibility
+type InternalRelayServer interface {
+	// ProxyRequest 是一个双向流式 RPC。
+	// "stream" 关键字表示客户端和服务器都可以连续地发送一系列消息，
+	// 这对于传输大文件或实时数据流（如视频）至关重要，可以避免将整个内容加载到内存中。
+	ProxyRequest(InternalRelay_ProxyRequestServer) error
+	mustEmbedUnimplementedInternalRelayServer()
+}
+
+// UnimplementedInternalRelayServer must be embedded to have forward compatible implementations.
+type UnimplementedInternalRelayServer struct {
+}
+
+func (UnimplementedInternalRelayServer) ProxyRequest(InternalRelay_ProxyRequestServer) error {
+	return status.Errorf(codes.Unimplemented, "method ProxyRequest not implemented")
+}
+func (UnimplementedInternalRelayServer) mustEmbedUnimplementedInternalRelayServer() {}
+
+// UnsafeInternalRelayServer may be embedded to opt out of forward compatibility for this service.
+// Use of this interface is not recommended, as added methods to InternalRelayServer will
+// result in compilation errors.
+type UnsafeInternalRelayServer interface {
+	mustEmbedUnimplementedInternalRelayServer()
+}
+
+func RegisterInternalRelayServer(s grpc.ServiceRegistrar, srv InternalRelayServer) {
+	s.RegisterService(&InternalRelay_ServiceDesc, srv)
+}
+
+func _InternalRelay_ProxyRequest_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(InternalRelayServer).ProxyRequest(&internalRelayProxyRequestServer{stream})
+}
+
+type InternalRelay_ProxyRequestServer interface {
+	Send(*ProxyResponseMessage) error
+	Recv() (*ProxyRequestMessage, error)
+	grpc.ServerStream
+}
+
+type internalRelayProxyRequestServer struct {
+	grpc.ServerStream
+}
+
+func (x *internalRelayProxyRequestServer) Send(m *ProxyResponseMessage) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *internalRelayProxyRequestServer) Recv() (*ProxyRequestMessage, error) {
+	m := new(ProxyRequestMessage)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+// InternalRelay_ServiceDesc is the grpc.ServiceDesc for InternalRelay service.
+// It's only intended for direct use with grpc.RegisterService,
+// and not to be introspected or modified (even as a copy)
+var InternalRelay_ServiceDesc = grpc.ServiceDesc{
+	ServiceName: "relay.InternalRelay",
+	HandlerType: (*InternalRelayServer)(nil),
+	Methods:     []grpc.MethodDesc{},
+	Streams: []grpc.StreamDesc{
+		{
+			StreamName:    "ProxyRequest",
+			Handler:       _InternalRelay_ProxyRequest_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
+	},
+	Metadata: "proto/relay.proto",
+}

session/manager.go

@@ -0,0 +1,167 @@
+package session
+
+import (
+	"context"
+	"log"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"strings"
+	"sync"
+
+	"github.com/hashicorp/yamux"
+)
+
+// SessionInfo 存储了一个活跃的设备连接所需的所有信息。
+// 我们将 yamux.Session 和 UserID 绑定在一起。
+type SessionInfo struct {
+	Session *yamux.Session
+	UserID  string
+}
+
+// Manager 是会话管理的核心结构体。
+// 它只负责管理本实例内存中的会话，不关心 Redis 或其他存储。
+type Manager struct {
+	// localSessions 使用设备 SN 作为 key，存储会话信息。
+	localSessions map[string]*SessionInfo
+	// sessionMutex 用于保护对 localSessions 的并发访问。
+	sessionMutex sync.RWMutex
+}
+
+// GlobalManager 是一个全局单例，方便在项目各处调用。
+var GlobalManager *Manager
+
+// InitManager 初始化全局的会P话管理器。
+func InitManager() {
+	GlobalManager = &Manager{
+		localSessions: make(map[string]*SessionInfo),
+	}
+	log.Println("Local session manager initialized.")
+}
+
+// AddSession 向管理器中添加一个新的设备会话。
+// 如果已存在同名会话，它会先关闭旧的，再添加新的。
+func (m *Manager) AddSession(deviceSN string, info *SessionInfo) {
+	m.sessionMutex.Lock()
+	defer m.sessionMutex.Unlock()
+
+	// 如果设备重连，旧的会话可能还存在，需要先关闭它
+	if oldInfo, exists := m.localSessions[deviceSN]; exists {
+		log.Printf("Device '%s' already has a local session, closing the old one.", deviceSN)
+		oldInfo.Session.Close()
+	}
+
+	m.localSessions[deviceSN] = info
+	log.Printf("Local session for device '%s' has been added.", deviceSN)
+}
+
+// RemoveSession 从管理器中移除一个设备会话。
+// 它会检查传入的 session 对象是否与当前存储的一致，防止误删新会话。
+func (m *Manager) RemoveSession(deviceSN string, session *yamux.Session) {
+	m.sessionMutex.Lock()
+	defer m.sessionMutex.Unlock()
+
+	// 这是一个重要的检查：确保我们删除的是正确的、已经过期的会话，
+	// 而不是一个刚刚建立的新会话（万一发生竞争）。
+	if currentInfo, exists := m.localSessions[deviceSN]; exists && currentInfo.Session == session {
+		delete(m.localSessions, deviceSN)
+		log.Printf("Local session for device '%s' has been removed.", deviceSN)
+	}
+}
+
+// GetLocalSession 根据设备 SN 查找一个活跃的本地会话。
+// 这是最常用的查询方法。
+func (m *Manager) GetLocalSession(deviceSN string) (*SessionInfo, bool) {
+	m.sessionMutex.RLock()
+	defer m.sessionMutex.RUnlock()
+
+	info, ok := m.localSessions[deviceSN]
+	if ok && !info.Session.IsClosed() {
+		// 确保会话不仅存在，而且是活跃的
+		return info, true
+	}
+	return nil, false
+}
+
+// CreateReverseProxy 是一个辅助函数，用于创建一个配置好的 httputil.ReverseProxy。
+// 将这个逻辑放在这里，是因为它与 SessionInfo 强相关，可以被 main.go 和 grpc/server.go 复用。
+func CreateReverseProxy(sessionInfo *SessionInfo, deviceSN string, originalPath string, originalQuery string) *httputil.ReverseProxy {
+	return &httputil.ReverseProxy{
+		// Director 负责在请求被转发前，修改请求的 URL、Header 等。
+		Director: func(req *http.Request) {
+			// [新增日志] 如果是 WebSocket 请求，就打印它
+			if isWebSocketRequest(req) { // isWebSocketRequest 是我们之前写的辅助函数
+				// true 表示连同 body 一起打印，对于握手请求 body 为空
+				reqDump, _ := httputil.DumpRequestOut(req, true)
+				log.Printf("--- [SUCCESS CASE] ReverseProxy is about to send this WebSocket request:\n%s\n-------------------------------------------------", string(reqDump))
+			}
+
+			// 从原始请求路径中解析出要转发到 immich 的真正路径
+			// 例如，从 "/tunnel/SN123/api/album" -> "/api/album"
+			pathParts := strings.SplitN(strings.TrimPrefix(originalPath, "/"), "/", 3)
+			if len(pathParts) > 2 {
+				req.URL.Path = "/" + pathParts[2]
+			} else {
+				req.URL.Path = "/"
+			}
+
+			req.URL.RawQuery = originalQuery // 传递原始的查询参数
+			req.URL.Scheme = "http"
+			// Host 不重要，因为我们下面会劫持网络连接 (DialContext)
+			req.URL.Host = "immich-internal"
+			// 设置 X-Real-IP 头，让 immich 知道原始客户端的 IP
+			req.Header.Set("X-Real-IP", req.RemoteAddr)
+		},
+
+		// Transport 负责实际的请求发送。我们通过重写 DialContext 来劫持它。
+		Transport: &http.Transport{
+			// 这是整个隧道转发的核心：
+			// 当 ReverseProxy 尝试建立一个 TCP 连接到 "immich-internal" 时，
+			// 我们不进行真正的网络拨号，而是直接在 yamux 会话上打开一个新的流 (stream)。
+			// 这个流就等同于一个虚拟的 TCP 连接，直接通往设备端的 immich 容器。
+			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				return sessionInfo.Session.Open()
+			},
+			// 必须禁用 HTTP/2，因为它与我们的简单流转发不兼容。
+			ForceAttemptHTTP2: false,
+		},
+
+		// FlushInterval 设置为 -1 会禁用缓冲，立即将数据块发送出去。
+		// 这对于视频流和 WebSocket 至关重要。
+		FlushInterval: -1,
+
+		// ModifyResponse 允许我们在响应返回给客户端之前修改它。
+		ModifyResponse: func(resp *http.Response) error {
+			// [新增调试日志]
+			// 这是一个关键探针！
+			if resp.StatusCode == http.StatusSwitchingProtocols { // 101
+				log.Printf("DEBUG (WebSocket): ModifyResponse received '101 Switching Protocols'. This means backend handshake was successful!")
+			}
+			// 这个 Header 告诉上游的代理（如 Nginx）不要缓冲这个响应。
+			resp.Header.Set("X-Accel-Buffering", "no")
+			return nil
+		},
+
+		// ErrorHandler 定义了当转发过程中发生错误（如设备端断开连接）时的处理逻辑。
+		ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
+			// [新增调试日志]
+			// 这是另一个关键探针！
+			if r.Header.Get("Upgrade") == "websocket" {
+				log.Printf("DEBUG (WebSocket): ErrorHandler was triggered for a WebSocket request. Error: %v", err)
+			}
+
+			log.Printf("ERROR: Reverse proxy error for device %s: %v", deviceSN, err)
+			http.Error(w, "Error forwarding request to device", http.StatusBadGateway)
+		},
+	}
+}
+
+// [新增] 确保 isWebSocketRequest 辅助函数存在于 session/manager.go
+func isWebSocketRequest(r *http.Request) bool {
+	upgradeHeader := strings.ToLower(r.Header.Get("Upgrade"))
+	if upgradeHeader != "websocket" {
+		return false
+	}
+	connectionHeader := strings.ToLower(r.Header.Get("Connection"))
+	return strings.Contains(connectionHeader, "upgrade")
+}

storage/redis.go

@@ -0,0 +1,126 @@
+// 文件: storage/redis.go
+package storage
+
+import (
+	"context"
+	"fmt"
+	"github.com/redis/go-redis/v9"
+	"log"
+	"memobus_relay_server/config" // 替换为你的模块名
+	"time"
+)
+
+// RedisManager 结构体封装了所有与 Redis 相关的操作
+type RedisManager struct {
+	Client     *redis.Client
+	sessionTTL time.Duration
+}
+
+// GlobalRedis 是一个全局可访问的 RedisManager 实例
+var GlobalRedis *RedisManager
+
+// InitRedis 初始化 Redis 连接并创建全局的 RedisManager 实例
+// 如果配置中 Redis 未启用，则返回 nil
+func InitRedis() error {
+	if !config.Cfg.Redis.Enabled {
+		log.Println("Redis is disabled in config. Skipping initialization.")
+		return nil
+
+	}
+
+	client := redis.NewClient(&redis.Options{
+		Addr:     config.Cfg.Redis.Addr,
+		Password: config.Cfg.Redis.Password,
+		DB:       config.Cfg.Redis.DB,
+	})
+
+	if err := client.Ping(context.Background()).Err(); err != nil {
+		return fmt.Errorf("failed to connect to Redis: %w", err)
+	}
+
+	GlobalRedis = &RedisManager{
+		Client:     client,
+		sessionTTL: time.Duration(config.Cfg.Redis.SessionTTLSeconds) * time.Second,
+	}
+
+	log.Println("Successfully connected to Redis.")
+	return nil
+}
+
+// getRedisKey 生成设备会话在 Redis 中的 key
+func getRedisKey(deviceSN string) string {
+	return fmt.Sprintf("device_session:%s", deviceSN)
+}
+
+// RegisterDeviceSession 将设备标记为在线
+// 在单机模式下，value 可以是一个简单的占位符，如 "online"
+func (m *RedisManager) RegisterDeviceSession(deviceSN string, value string) error {
+	key := getRedisKey(deviceSN)
+	err := m.Client.Set(context.Background(), key, value, m.sessionTTL).Err()
+	if err != nil {
+		return fmt.Errorf("failed to register device '%s' to Redis: %w", deviceSN, err)
+	}
+	log.Printf("Device '%s' registered in Redis.", deviceSN)
+	return nil
+}
+
+// DeregisterDeviceSession 从 Redis 中移除设备会话
+func (m *RedisManager) DeregisterDeviceSession(deviceSN string) {
+	key := getRedisKey(deviceSN)
+	m.Client.Del(context.Background(), key)
+	log.Printf("Device '%s' deregistered from Redis.", deviceSN)
+}
+
+// IsDeviceOnline 检查设备是否在 Redis 中被标记为在线
+func (m *RedisManager) IsDeviceOnline(deviceSN string) (bool, error) {
+	key := getRedisKey(deviceSN)
+	val, err := m.Client.Get(context.Background(), key).Result()
+	if err == redis.Nil {
+		return false, nil // Key 不存在，明确表示不在线
+	}
+	if err != nil {
+		return false, fmt.Errorf("redis error looking up device '%s': %w", deviceSN, err)
+	}
+	return val != "", nil // 只要 key 存在且值不为空，就认为在线
+}
+
+// [新增] GetDeviceOwner 函数，用来获取持有连接的实例 ID
+func (m *RedisManager) GetDeviceOwner(deviceSN string) (string, error) {
+	key := getRedisKey(deviceSN)
+	instanceID, err := m.Client.Get(context.Background(), key).Result()
+	if err != nil {
+		// 让调用者处理 redis.Nil 错误，这表示设备未找到
+		return "", err
+	}
+	return instanceID, nil
+}
+
+// KeepAliveSession 启动一个 goroutine，为给定的设备会话在 Redis 中定期续期
+func (m *RedisManager) KeepAliveSession(closeChan <-chan struct{}, deviceSN string) {
+	// 以 TTL 的一半作为续期间隔
+	ticker := time.NewTicker(m.sessionTTL / 2)
+	defer ticker.Stop()
+
+	key := getRedisKey(deviceSN)
+	log.Printf("Starting Redis keep-alive for device '%s'.", deviceSN)
+
+	for {
+		select {
+		case <-ticker.C:
+			// 为 key 续期
+			err := m.Client.Expire(context.Background(), key, m.sessionTTL).Err()
+			if err != nil {
+				// 如果 key 不存在了（可能被手动删除或过期），就没必要再续了
+				if err == redis.Nil {
+					log.Printf("Redis key for %s no longer exists, stopping keep-alive.", deviceSN)
+					return
+				}
+				log.Printf("ERROR: Failed to refresh session TTL for %s in Redis: %v", deviceSN, err)
+			}
+		case <-closeChan:
+			// session 关闭了，退出 goroutine
+			log.Printf("Stopping Redis keep-alive for device '%s' due to session close.", deviceSN)
+			return
+		}
+	}
+}