feat(logging): make error-logs-max-files configurable

- Add ErrorLogsMaxFiles config field with default value 10
- Support hot-reload via config file changes
- Add Management API: GET/PUT/PATCH /v0/management/error-logs-max-files
- Maintain SDK backward compatibility with NewFileRequestLogger (3 params)
- Add NewFileRequestLoggerWithOptions for custom error log retention

When request logging is disabled, forced error logs are retained up to
the configured limit. Set to 0 to disable cleanup.

config.example.yaml

@@ -50,6 +50,10 @@ logging-to-file: false
 # files are deleted until within the limit. Set to 0 to disable.
 logs-max-total-size-mb: 0
 
+# Maximum number of error log files retained when request logging is disabled.
+# When exceeded, the oldest error log files are deleted. Default is 10. Set to 0 to disable cleanup.
+error-logs-max-files: 10
+
 # When false, disable in-memory usage statistics aggregation
 usage-statistics-enabled: false
 

examples/custom-provider/main.go

@@ -205,7 +205,7 @@ func main() {
 			// Optional: add a simple middleware + custom request logger
 			api.WithMiddleware(func(c *gin.Context) { c.Header("X-Example", "custom-provider"); c.Next() }),
 			api.WithRequestLoggerFactory(func(cfg *config.Config, cfgPath string) logging.RequestLogger {
-				return logging.NewFileRequestLogger(true, "logs", filepath.Dir(cfgPath))
+				return logging.NewFileRequestLoggerWithOptions(true, "logs", filepath.Dir(cfgPath), cfg.ErrorLogsMaxFiles)
 			}),
 		).
 		WithHooks(hooks).

internal/api/handlers/management/config_basic.go

@@ -222,6 +222,26 @@ func (h *Handler) PutLogsMaxTotalSizeMB(c *gin.Context) {
 	h.persist(c)
 }
 
+// ErrorLogsMaxFiles
+func (h *Handler) GetErrorLogsMaxFiles(c *gin.Context) {
+	c.JSON(200, gin.H{"error-logs-max-files": h.cfg.ErrorLogsMaxFiles})
+}
+func (h *Handler) PutErrorLogsMaxFiles(c *gin.Context) {
+	var body struct {
+		Value *int `json:"value"`
+	}
+	if errBindJSON := c.ShouldBindJSON(&body); errBindJSON != nil || body.Value == nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid body"})
+		return
+	}
+	value := *body.Value
+	if value < 0 {
+		value = 10
+	}
+	h.cfg.ErrorLogsMaxFiles = value
+	h.persist(c)
+}
+
 // Request log
 func (h *Handler) GetRequestLog(c *gin.Context) { c.JSON(200, gin.H{"request-log": h.cfg.RequestLog}) }
 func (h *Handler) PutRequestLog(c *gin.Context) {

internal/api/server.go

@@ -60,9 +60,9 @@ type ServerOption func(*serverOptionConfig)
 func defaultRequestLoggerFactory(cfg *config.Config, configPath string) logging.RequestLogger {
 	configDir := filepath.Dir(configPath)
 	if base := util.WritablePath(); base != "" {
-		return logging.NewFileRequestLogger(cfg.RequestLog, filepath.Join(base, "logs"), configDir)
+		return logging.NewFileRequestLogger(cfg.RequestLog, filepath.Join(base, "logs"), configDir, cfg.ErrorLogsMaxFiles)
 	}
-	return logging.NewFileRequestLogger(cfg.RequestLog, "logs", configDir)
+	return logging.NewFileRequestLogger(cfg.RequestLog, "logs", configDir, cfg.ErrorLogsMaxFiles)
 }
 
 // WithMiddleware appends additional Gin middleware during server construction.
@@ -497,6 +497,10 @@ func (s *Server) registerManagementRoutes() {
 		mgmt.PUT("/logs-max-total-size-mb", s.mgmt.PutLogsMaxTotalSizeMB)
 		mgmt.PATCH("/logs-max-total-size-mb", s.mgmt.PutLogsMaxTotalSizeMB)
 
+		mgmt.GET("/error-logs-max-files", s.mgmt.GetErrorLogsMaxFiles)
+		mgmt.PUT("/error-logs-max-files", s.mgmt.PutErrorLogsMaxFiles)
+		mgmt.PATCH("/error-logs-max-files", s.mgmt.PutErrorLogsMaxFiles)
+
 		mgmt.GET("/usage-statistics-enabled", s.mgmt.GetUsageStatisticsEnabled)
 		mgmt.PUT("/usage-statistics-enabled", s.mgmt.PutUsageStatisticsEnabled)
 		mgmt.PATCH("/usage-statistics-enabled", s.mgmt.PutUsageStatisticsEnabled)
@@ -907,6 +911,15 @@ func (s *Server) UpdateClients(cfg *config.Config) {
 		}
 	}
 
+	if s.requestLogger != nil && (oldCfg == nil || oldCfg.ErrorLogsMaxFiles != cfg.ErrorLogsMaxFiles) {
+		if setter, ok := s.requestLogger.(interface{ SetErrorLogsMaxFiles(int) }); ok {
+			setter.SetErrorLogsMaxFiles(cfg.ErrorLogsMaxFiles)
+		}
+		if oldCfg != nil {
+			log.Debugf("error_logs_max_files updated from %d to %d", oldCfg.ErrorLogsMaxFiles, cfg.ErrorLogsMaxFiles)
+		}
+	}
+
 	if oldCfg == nil || oldCfg.DisableCooling != cfg.DisableCooling {
 		auth.SetQuotaCooldownDisabled(cfg.DisableCooling)
 		if oldCfg != nil {

internal/config/config.go

@@ -51,6 +51,10 @@ type Config struct {
 	// When exceeded, the oldest log files are deleted until within the limit. Set to 0 to disable.
 	LogsMaxTotalSizeMB int `yaml:"logs-max-total-size-mb" json:"logs-max-total-size-mb"`
 
+	// ErrorLogsMaxFiles limits the number of error log files retained when request logging is disabled.
+	// When exceeded, the oldest error log files are deleted. Default is 10. Set to 0 to disable cleanup.
+	ErrorLogsMaxFiles int `yaml:"error-logs-max-files" json:"error-logs-max-files"`
+
 	// UsageStatisticsEnabled toggles in-memory usage aggregation; when false, usage data is discarded.
 	UsageStatisticsEnabled bool `yaml:"usage-statistics-enabled" json:"usage-statistics-enabled"`
 
@@ -502,6 +506,7 @@ func LoadConfigOptional(configFile string, optional bool) (*Config, error) {
 	cfg.Host = "" // Default empty: binds to all interfaces (IPv4 + IPv6)
 	cfg.LoggingToFile = false
 	cfg.LogsMaxTotalSizeMB = 0
+	cfg.ErrorLogsMaxFiles = 10
 	cfg.UsageStatisticsEnabled = false
 	cfg.DisableCooling = false
 	cfg.AmpCode.RestrictManagementToLocalhost = false // Default to false: API key auth is sufficient
@@ -550,6 +555,10 @@ func LoadConfigOptional(configFile string, optional bool) (*Config, error) {
 		cfg.LogsMaxTotalSizeMB = 0
 	}
 
+	if cfg.ErrorLogsMaxFiles < 0 {
+		cfg.ErrorLogsMaxFiles = 10
+	}
+
 	// Sync request authentication providers with inline API keys for backwards compatibility.
 	syncInlineAccessProvider(&cfg)
 

internal/logging/request_logger.go

@@ -132,6 +132,9 @@ type FileRequestLogger struct {
 
 	// logsDir is the directory where log files are stored.
 	logsDir string
+
+	// errorLogsMaxFiles limits the number of error log files retained.
+	errorLogsMaxFiles int
 }
 
 // NewFileRequestLogger creates a new file-based request logger.
@@ -141,10 +144,11 @@ type FileRequestLogger struct {
 //   - logsDir: The directory where log files should be stored (can be relative)
 //   - configDir: The directory of the configuration file; when logsDir is
 //     relative, it will be resolved relative to this directory
+//   - errorLogsMaxFiles: Maximum number of error log files to retain (0 = no cleanup)
 //
 // Returns:
 //   - *FileRequestLogger: A new file-based request logger instance
-func NewFileRequestLogger(enabled bool, logsDir string, configDir string) *FileRequestLogger {
+func NewFileRequestLogger(enabled bool, logsDir string, configDir string, errorLogsMaxFiles int) *FileRequestLogger {
 	// Resolve logsDir relative to the configuration file directory when it's not absolute.
 	if !filepath.IsAbs(logsDir) {
 		// If configDir is provided, resolve logsDir relative to it.
@@ -153,8 +157,9 @@ func NewFileRequestLogger(enabled bool, logsDir string, configDir string) *FileR
 		}
 	}
 	return &FileRequestLogger{
-		enabled: enabled,
-		logsDir: logsDir,
+		enabled:           enabled,
+		logsDir:           logsDir,
+		errorLogsMaxFiles: errorLogsMaxFiles,
 	}
 }
 
@@ -175,6 +180,11 @@ func (l *FileRequestLogger) SetEnabled(enabled bool) {
 	l.enabled = enabled
 }
 
+// SetErrorLogsMaxFiles updates the maximum number of error log files to retain.
+func (l *FileRequestLogger) SetErrorLogsMaxFiles(maxFiles int) {
+	l.errorLogsMaxFiles = maxFiles
+}
+
 // LogRequest logs a complete non-streaming request/response cycle to a file.
 //
 // Parameters:
@@ -433,8 +443,12 @@ func (l *FileRequestLogger) sanitizeForFilename(path string) string {
 	return sanitized
 }
 
-// cleanupOldErrorLogs keeps only the newest 10 forced error log files.
+// cleanupOldErrorLogs keeps only the newest errorLogsMaxFiles forced error log files.
 func (l *FileRequestLogger) cleanupOldErrorLogs() error {
+	if l.errorLogsMaxFiles <= 0 {
+		return nil
+	}
+
 	entries, errRead := os.ReadDir(l.logsDir)
 	if errRead != nil {
 		return errRead
@@ -462,7 +476,7 @@ func (l *FileRequestLogger) cleanupOldErrorLogs() error {
 		files = append(files, logFile{name: name, modTime: info.ModTime()})
 	}
 
-	if len(files) <= 10 {
+	if len(files) <= l.errorLogsMaxFiles {
 		return nil
 	}
 
@@ -470,7 +484,7 @@ func (l *FileRequestLogger) cleanupOldErrorLogs() error {
 		return files[i].modTime.After(files[j].modTime)
 	})
 
-	for _, file := range files[10:] {
+	for _, file := range files[l.errorLogsMaxFiles:] {
 		if errRemove := os.Remove(filepath.Join(l.logsDir, file.name)); errRemove != nil {
 			log.WithError(errRemove).Warnf("failed to remove old error log: %s", file.name)
 		}

sdk/logging/request_logger.go

@@ -3,6 +3,8 @@ package logging
 
 import internallogging "github.com/router-for-me/CLIProxyAPI/v6/internal/logging"
 
+const defaultErrorLogsMaxFiles = 10
+
 // RequestLogger defines the interface for logging HTTP requests and responses.
 type RequestLogger = internallogging.RequestLogger
 
@@ -12,7 +14,12 @@ type StreamingLogWriter = internallogging.StreamingLogWriter
 // FileRequestLogger implements RequestLogger using file-based storage.
 type FileRequestLogger = internallogging.FileRequestLogger
 
-// NewFileRequestLogger creates a new file-based request logger.
+// NewFileRequestLogger creates a new file-based request logger with default error log retention (10 files).
 func NewFileRequestLogger(enabled bool, logsDir string, configDir string) *FileRequestLogger {
-	return internallogging.NewFileRequestLogger(enabled, logsDir, configDir)
+	return internallogging.NewFileRequestLogger(enabled, logsDir, configDir, defaultErrorLogsMaxFiles)
+}
+
+// NewFileRequestLoggerWithOptions creates a new file-based request logger with configurable error log retention.
+func NewFileRequestLoggerWithOptions(enabled bool, logsDir string, configDir string, errorLogsMaxFiles int) *FileRequestLogger {
+	return internallogging.NewFileRequestLogger(enabled, logsDir, configDir, errorLogsMaxFiles)
 }