Nginx config's
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Your Business</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<!--# if expr="$status = 502" -->
<meta http-equiv="refresh" content="5">
<!--# endif -->
</head>
<body>
<!--# if expr="$status = 502" -->
<h1>We are updating our website </h1>
<p>This is only for a few seconds, you will be redirected.</p>
<!--# else -->
<h1><!--# echo var="status" default="" --> <!--# echo var="status_text" default="Something goes wrong" --></h1>
<!--# endif -->
</body>
</html>