feat(middleware): add CDNJS middleware for handling specific paths

internal/middleware/cdnjs.go

@@ -0,0 +1,93 @@
+package middleware
+
+import (
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+)
+
+type CDNJSConfig struct {
+	Path       string // 固定路径，例如 "/cdnjs"
+	TargetHost string // 目标主机，例如 "cdnjs.cloudflare.com"
+	TargetURL  string // 目标URL，例如 "https://cdnjs.cloudflare.com"
+}
+
+// CDNJSMiddleware 处理固定路径的代理
+func CDNJSMiddleware(configs []CDNJSConfig) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// 检查是否匹配任何固定路径
+			for _, cfg := range configs {
+				if strings.HasPrefix(r.URL.Path, cfg.Path) {
+					// 创建新的请求
+					targetPath := strings.TrimPrefix(r.URL.Path, cfg.Path)
+					targetURL := cfg.TargetURL + targetPath
+
+					proxyReq, err := http.NewRequest(r.Method, targetURL, r.Body)
+					if err != nil {
+						http.Error(w, "Error creating proxy request", http.StatusInternalServerError)
+						return
+					}
+
+					// 复制原始请求的 header
+					for key, values := range r.Header {
+						for _, value := range values {
+							proxyReq.Header.Add(key, value)
+						}
+					}
+
+					// 设置必要的头部
+					proxyReq.Host = cfg.TargetHost
+					proxyReq.Header.Set("Host", cfg.TargetHost)
+					proxyReq.Header.Set("X-Real-IP", getClientIP(r))
+					proxyReq.Header.Set("X-Scheme", r.URL.Scheme)
+
+					// 发送代理请求
+					client := &http.Client{}
+					resp, err := client.Do(proxyReq)
+					if err != nil {
+						http.Error(w, "Error forwarding request", http.StatusBadGateway)
+						return
+					}
+					defer resp.Body.Close()
+
+					// 复制响应头
+					for key, values := range resp.Header {
+						for _, value := range values {
+							w.Header().Add(key, value)
+						}
+					}
+
+					// 设置响应状态码
+					w.WriteHeader(resp.StatusCode)
+
+					// 复制响应体
+					if _, err := io.Copy(w, resp.Body); err != nil {
+						// 已经发送了响应头，只能记录错误
+						log.Printf("Error copying response: %v", err)
+					}
+					return
+				}
+			}
+
+			// 如果没有匹配的固定路径，继续下一个处理器
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// getClientIP 获取客户端IP
+func getClientIP(r *http.Request) string {
+	if ip := r.Header.Get("X-Real-IP"); ip != "" {
+		return ip
+	}
+	if ip := r.Header.Get("X-Forwarded-For"); ip != "" {
+		return strings.Split(ip, ",")[0]
+	}
+	if ip, _, err := net.SplitHostPort(r.RemoteAddr); err == nil {
+		return ip
+	}
+	return r.RemoteAddr
+}

main.go

@@ -9,6 +9,7 @@ import (
 	"proxy-go/internal/config"
 	"proxy-go/internal/handler"
 	"proxy-go/internal/middleware"
+	"strings"
 	"syscall"
 )
 
@@ -19,7 +20,7 @@ func main() {
 		log.Fatal("Error loading config:", err)
 	}
 
-	// 创建压缩管理器，直接使用配置文件中的压缩配置
+	// 创建压缩管理器
 	compManager := compression.NewManager(compression.Config{
 		Gzip:   compression.CompressorConfig(cfg.Compression.Gzip),
 		Brotli: compression.CompressorConfig(cfg.Compression.Brotli),
@@ -28,8 +29,34 @@ func main() {
 	// 创建代理处理器
 	proxyHandler := handler.NewProxyHandler(cfg.MAP)
 
-	// 添加中间件
-	var handler http.Handler = proxyHandler
+	// 创建 CDNJS 中间件配置
+	cdnjsConfigs := []middleware.CDNJSConfig{
+		{
+			Path:       "/cdnjs",
+			TargetHost: "cdnjs.cloudflare.com",
+			TargetURL:  "https://cdnjs.cloudflare.com",
+		},
+		{
+			Path:       "/jsdelivr",
+			TargetHost: "cdn.jsdelivr.net",
+			TargetURL:  "https://cdn.jsdelivr.net",
+		},
+	}
+
+	// 创建主处理器
+	mainHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasPrefix(r.URL.Path, "/cdnjs") {
+			// CDNJS 请求使用 CDNJS 中间件处理
+			handler := middleware.CDNJSMiddleware(cdnjsConfigs)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+			handler.ServeHTTP(w, r)
+		} else {
+			// 非 CDNJS 请求使用普通代理处理器
+			proxyHandler.ServeHTTP(w, r)
+		}
+	})
+
+	// 对非 CDNJS 请求添加压缩中间件
+	var handler http.Handler = mainHandler
 	if cfg.Compression.Gzip.Enabled || cfg.Compression.Brotli.Enabled {
 		handler = middleware.CompressionMiddleware(compManager)(handler)
 	}