From 5e8d8d070a6fc83e933985406d50a77be0285416 Mon Sep 17 00:00:00 2001
From: Kuingsmile <96409857+Kuingsmile@users.noreply.github.com>
Date: Wed, 18 Jun 2025 20:37:16 +0800
Subject: [PATCH] feat(log): add error logging middleware for improved error
 handling (#182)

---
 cmd/server.go                   |  2 ++
 server/middlewares/error_log.go | 56 +++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 server/middlewares/error_log.go

diff --git a/cmd/server.go b/cmd/server.go
index 15fd37a9..ea5138fe 100644
--- a/cmd/server.go
+++ b/cmd/server.go
@@ -19,6 +19,7 @@ import (
 	"github.com/OpenListTeam/OpenList/internal/fs"
 	"github.com/OpenListTeam/OpenList/pkg/utils"
 	"github.com/OpenListTeam/OpenList/server"
+	"github.com/OpenListTeam/OpenList/server/middlewares"
 	"github.com/OpenListTeam/sftpd-openlist"
 	ftpserver "github.com/fclairamb/ftpserverlib"
 	"github.com/gin-gonic/gin"
@@ -47,6 +48,7 @@ the address is defined in config file`,
 			gin.SetMode(gin.ReleaseMode)
 		}
 		r := gin.New()
+		r.Use(middlewares.ErrorLogging())
 		r.Use(gin.LoggerWithWriter(log.StandardLogger().Out), gin.RecoveryWithWriter(log.StandardLogger().Out))
 		server.Init(r)
 		var httpHandler http.Handler = r
diff --git a/server/middlewares/error_log.go b/server/middlewares/error_log.go
new file mode 100644
index 00000000..f696e326
--- /dev/null
+++ b/server/middlewares/error_log.go
@@ -0,0 +1,56 @@
+package middlewares
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"github.com/gin-gonic/gin"
+	log "github.com/sirupsen/logrus"
+)
+
+func ErrorLogging() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		w := &responseBodyWriter{body: &bytes.Buffer{}, ResponseWriter: c.Writer}
+		c.Writer = w
+		c.Next()
+		var errorMsg string
+		if w.body.Len() > 0 {
+			var jsonBody struct {
+				Code    int    `json:"code"`
+				Message string `json:"message"`
+			}
+			if err := json.Unmarshal(w.body.Bytes(), &jsonBody); err == nil {
+				if jsonBody.Code != 200 {
+					errorMsg = fmt.Sprintf(" error: code=%d, message=%s", jsonBody.Code, jsonBody.Message)
+				}
+			}
+		}
+		if c.Writer.Status() >= 400 {
+			if len(c.Errors) > 0 {
+				errorMsg = c.Errors.String()
+			} else if errorMsg == "" && w.body.Len() > 0 {
+				body := w.body.String()
+				if len(body) > 500 {
+					errorMsg = body[:500] + "..."
+				} else {
+					errorMsg = body
+				}
+			}
+		}
+
+		if errorMsg != "" {
+			log.Error(errorMsg)
+		}
+	}
+}
+
+type responseBodyWriter struct {
+	gin.ResponseWriter
+	body *bytes.Buffer
+}
+
+func (r *responseBodyWriter) Write(b []byte) (int, error) {
+	r.body.Write(b)
+	return r.ResponseWriter.Write(b)
+}