add Compress option to FileLogConfig

config.go

@@ -35,6 +35,9 @@ type FileLogConfig struct {
 	MaxDays int `toml:"max-days" json:"max-days"`
 	// Maximum number of old log files to retain.
 	MaxBackups int `toml:"max-backups" json:"max-backups"`
+	// Compress determines if the rotated log files should be compressed
+	// using gzip. The default is not to perform compression.
+	Compress bool `toml:"compress" json:"compress"`
 }
 
 // Config serializes log related config in toml/json.

log.go

@@ -126,6 +126,7 @@ func initFileLog(cfg *FileLogConfig) (*lumberjack.Logger, error) {
 		MaxBackups: cfg.MaxBackups,
 		MaxAge:     cfg.MaxDays,
 		LocalTime:  true,
+		Compress:   cfg.Compress,
 	}, nil
 }