add subscription pattern to acls,fix NaN value in metrics for uptime,get real iface name for mac

logic/util.go

@@ -218,3 +218,11 @@ func StringDifference(a, b []string) []string {
 	}
 	return diff
 }
+
+// CheckIfFileExists - checks if file exists or no in the given path
+func CheckIfFileExists(filePath string) bool {
+	if _, err := os.Stat(filePath); os.IsNotExist(err) {
+		return false
+	}
+	return true
+}