Add internal/middleware/request_id.go

internal/middleware/request_id.go

@@ -0,0 +1,45 @@
+package middleware
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+
+	"github.com/gin-gonic/gin"
+)
+
+// RequestIDHeader 请求 ID 的响应头名称
+const RequestIDHeader = "X-Request-ID"
+
+// RequestIDContextKey 上下文中存储请求 ID 的键
+const RequestIDContextKey = "request_id"
+
+// RequestID 为每个请求生成唯一 ID，写入上下文和响应头
+func RequestID() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// 优先从请求头读取上游传入的 request_id
+		rid := c.GetHeader(RequestIDHeader)
+		if rid == "" {
+			rid = generateRequestID()
+		}
+		c.Set(RequestIDContextKey, rid)
+		c.Header(RequestIDHeader, rid)
+		c.Next()
+	}
+}
+
+// GetRequestID 从 gin.Context 中获取请求 ID
+func GetRequestID(c *gin.Context) string {
+	if rid, exists := c.Get(RequestIDContextKey); exists {
+		if s, ok := rid.(string); ok {
+			return s
+		}
+	}
+	return ""
+}
+
+// generateRequestID 生成 16 字节随机 hex 请求 ID
+func generateRequestID() string {
+	b := make([]byte, 16)
+	_, _ = rand.Read(b)
+	return hex.EncodeToString(b)
+}