section-io-gists/CustomMaintenancePage.vcl

## CustomMaintenancePage.vcl
import std;

acl whitelist {
    "123.123.123.123";
    "216.3.128.12";
}

sub vcl_recv {
  # If not a whitelisted IP, then display maintenance page. Requires std library.
  if(std.ip(regsub(req.http.X-Forwarded-For, "[, ].*$", ""), client.ip) !~ whitelist) {
    return (synth(800, "Maintenance page"));
  }
}

sub vcl_synth {
    if (resp.status == 800) {
      set resp.http.Content-Type = "text/html; charset=utf-8";
      set resp.status = 503;
      set resp.http.Cache-Control = "no-store, no-cache, must-revalidate, post-check=0, pre-check=0, max-age=0";
      synthetic( {"
        <html><head></head>
        <body>
        Sorry this website is currently under going maintenance, please try again soon.
        </body></html>
        "} );
      return (deliver);
   }
}
	import std;

	acl whitelist {
	"123.123.123.123";
	"216.3.128.12";
	}

	sub vcl_recv {
	# If not a whitelisted IP, then display maintenance page. Requires std library.
	if(std.ip(regsub(req.http.X-Forwarded-For, "[, ].*$", ""), client.ip) !~ whitelist) {
	return (synth(800, "Maintenance page"));
	}
	}

	sub vcl_synth {
	if (resp.status == 800) {
	set resp.http.Content-Type = "text/html; charset=utf-8";
	set resp.status = 503;
	set resp.http.Cache-Control = "no-store, no-cache, must-revalidate, post-check=0, pre-check=0, max-age=0";
	synthetic( {"
	<html><head></head>
	<body>
	Sorry this website is currently under going maintenance, please try again soon.
	</body></html>
	"} );
	return (deliver);
	}
	}