签入脚本

internal/middleware/ratelimit.go

@@ -0,0 +1,102 @@
+package middleware
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/gogf/gf/v2/errors/gerror"
+	"github.com/gogf/gf/v2/net/ghttp"
+
+	"easygoadmin/internal/consts"
+	"easygoadmin/utility/cache"
+	"easygoadmin/utility/response"
+)
+
+// ============================== API 限流中间件 ==============================
+//
+// 固定窗口计数：键按窗口起点对齐（ratelimit:{ip}:{path}:{窗口起点}），
+// 计数存 utility/cache（Redis 优先、内存降级），多实例部署时共享计数。
+//
+// 规则：
+//   - 仅限 /api/ 前缀接口；文档（/api.json）、静态资源、健康检查不受限
+//   - 认证入口（登录/验证码/令牌兑换）按 rateLimit.authLimit 单独更严阈值
+//   - 计数存储异常时放行（限流不阻断业务）
+
+// RateLimit API 限流
+func RateLimit(r *ghttp.Request) {
+	if !cfgBool(r.Context(), "rateLimit.enable", true) {
+		r.Middleware.Next()
+		return
+	}
+	path := r.URL.Path
+	if !isRateLimitedPath(path) {
+		r.Middleware.Next()
+		return
+	}
+	window := cfgInt(r.Context(), "rateLimit.windowSeconds", 60)
+	limit := cfgInt(r.Context(), "rateLimit.limit", 120)
+	if isAuthPath(path) {
+		limit = cfgInt(r.Context(), "rateLimit.authLimit", 10)
+	}
+	if limit <= 0 || window <= 0 {
+		r.Middleware.Next()
+		return
+	}
+
+	// 窗口起点对齐：同一窗口内共享计数键
+	windowStart := time.Now().Unix() / int64(window) * int64(window)
+	key := fmt.Sprintf("ratelimit:%s:%s:%d", realClientIP(r), path, windowStart)
+	n, err := incrCounter(r, key, window)
+	if err != nil {
+		r.Middleware.Next()
+		return
+	}
+	if n > int64(limit) {
+		response.Write(r, response.Fail(gerror.NewCode(consts.CodeTooManyRequests)))
+		return
+	}
+	r.Middleware.Next()
+}
+
+// isRateLimitedPath 判断是否为参与限流的接口路径
+// /api.json 与 /swagger 不带 /api/ 前缀，自然排除；健康检查显式豁免
+func isRateLimitedPath(path string) bool {
+	if path == "/api/health" {
+		return false
+	}
+	return path == "/api" || strings.HasPrefix(path, "/api/")
+}
+
+// isAuthPath 判断是否为认证入口（适用更严格的独立阈值）
+func isAuthPath(path string) bool {
+	switch path {
+	case "/api/login", "/api/captcha", "/api/oauth2/token":
+		return true
+	}
+	return false
+}
+
+// incrCounter 固定窗口计数自增
+// 键已含窗口起点，TTL 仅用于回收存储，续期不影响窗口归属
+func incrCounter(r *ghttp.Request, key string, windowSeconds int) (int64, error) {
+	ttl := windowSeconds + 5
+	if raw, ok := cache.Get(r.Context(), key); ok {
+		n, _ := strconv.ParseInt(raw, 10, 64)
+		n++
+		_ = cache.Set(r.Context(), key, strconv.FormatInt(n, 10), ttl)
+		return n, nil
+	}
+	if cache.SetNX(r.Context(), key, "1", ttl) {
+		return 1, nil
+	}
+	// 并发下 SetNX 未抢到：读现值再加一
+	if raw, ok := cache.Get(r.Context(), key); ok {
+		n, _ := strconv.ParseInt(raw, 10, 64)
+		n++
+		_ = cache.Set(r.Context(), key, strconv.FormatInt(n, 10), ttl)
+		return n, nil
+	}
+	return 1, nil
+}