完善日志和审计链路

backend/internal/middleware/request_id.go

@@ -0,0 +1,45 @@
+package middleware
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+
+	"github.com/gin-gonic/gin"
+)
+
+const (
+	RequestIDHeader  = "X-Request-ID"
+	ContextRequestID = "request_id"
+)
+
+func RequestID() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		requestID := c.GetHeader(RequestIDHeader)
+		if requestID == "" {
+			requestID = newRequestID()
+		}
+		c.Set(ContextRequestID, requestID)
+		c.Writer.Header().Set(RequestIDHeader, requestID)
+		c.Next()
+	}
+}
+
+func GetRequestID(c *gin.Context) string {
+	value, ok := c.Get(ContextRequestID)
+	if !ok {
+		return ""
+	}
+	requestID, ok := value.(string)
+	if !ok {
+		return ""
+	}
+	return requestID
+}
+
+func newRequestID() string {
+	buf := make([]byte, 16)
+	if _, err := rand.Read(buf); err != nil {
+		return ""
+	}
+	return hex.EncodeToString(buf)
+}