If you discovered that proxying your webserver with varnish breaks PhpMyAdmin I’ve got the solution:

Problem is that the backend webserver, apache2 or nginx doesn’t even know it’s running behind another software.

Varnish does a completely normal request to webserver. Most times this isn’t any problem at all.

PhpMyAdmin tries to be “smart” and figure out its absolute URL and I run the apache2 or nginx backend on port 80.

The solution is to force an URL.

Add the following line to “config.inc.php“, changing the obvious:

$cfg['PmaAbsoluteUri'] = 'http://yourdomain.com/phpmyadmin/';

Enjoy!