Refine logger debug mode

Author: web-flow

is.go

@@ -55,7 +55,8 @@ var (
 )
 
 func init() {
-	if os.Getenv("DEBUG") != "" {
+	debug := os.Getenv("DEBUG")
+	if debug == "true" || debug == "1" || debug == "on" {
 		logger.EnableDebug()
 	}
 }