세션 IP 표시와 로그아웃 처리 보강

backend/internal/middleware/audit_middleware.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"log/slog"
 	"reflect"
-	"strings"
 	"sync"
 	"time"
 
@@ -217,16 +216,5 @@ func AuditMiddleware(config AuditConfig) fiber.Handler {
 }
 
 func extractClientIP(c *fiber.Ctx) string {
-	if forwarded := c.Get("X-Forwarded-For"); forwarded != "" {
-		parts := strings.Split(forwarded, ",")
-		if len(parts) > 0 {
-			if ip := strings.TrimSpace(parts[0]); ip != "" {
-				return ip
-			}
-		}
-	}
-	if realIP := strings.TrimSpace(c.Get("X-Real-IP")); realIP != "" {
-		return realIP
-	}
-	return c.IP()
+	return utils.ResolveClientIP(c.Get("X-Forwarded-For"), c.Get("X-Real-IP"), c.IP())
 }

backend/internal/middleware/audit_middleware_test.go

@@ -117,6 +117,30 @@ func TestAuditMiddleware(t *testing.T) {
 		mockRepo.AssertExpectations(t)
 	})
 
+	t.Run("POST request - Prefer public forwarded IP", func(t *testing.T) {
+		app := fiber.New()
+		mockRepo := new(MockAuditRepository)
+
+		app.Use(AuditMiddleware(AuditConfig{
+			Repo: mockRepo,
+		}))
+
+		app.Post("/test", func(c *fiber.Ctx) error {
+			return c.SendStatus(fiber.StatusOK)
+		})
+
+		mockRepo.On("Create", mock.MatchedBy(func(log *domain.AuditLog) bool {
+			return log.IPAddress == "203.0.113.25"
+		})).Return(nil)
+
+		req := httptest.NewRequest("POST", "/test", nil)
+		req.Header.Set("X-Forwarded-For", "100.100.100.1, 203.0.113.25")
+
+		resp, _ := app.Test(req)
+		assert.Equal(t, fiber.StatusOK, resp.StatusCode)
+		mockRepo.AssertExpectations(t)
+	})
+
 	t.Run("POST request - Sync Failure (Strict Mode)", func(t *testing.T) {
 		app := fiber.New()
 		mockRepo := new(MockAuditRepository)