SERVER_NAME and SERVER_PORT woes

server_name_and_port.php

<?php

/**
 * Problem: there's code out there that relies on $_SERVER['SERVER_NAME'] and sometimes $_SERVER['SERVER_PORT']
 * to construct urls, either to "call itself" or to create urls that are passed to third parties and expect to
 * be routed back.
 *
 * This doesn't work well on Pantheon because the environmental data will be for ephemeral container data.
 *
 * In general, you don't want your code to rely on this, but if you are using some piece of contrib you may
 * not have a choice. In that case, you will need to do something in your `settings.php` or `wp-config.php`
 * to insure that the right values are present.
 *
 * Some possible solutions below.
 */

/**
 * 1) Use HTTP_HOST instead of SERVER_NAME
 *
 * Note that $_ENV will also be around for command-line uses. $_SERVER is only set up when handling a web
 * initiated request.
 */

$_SERVER['SERVER_NAME'] = $_SERVER['HTTP_HOST'];

/**
 * 2) Setting the SERVER_PORT correctly
 */

if (isset($_SERVER['PANTHEON_ENVIRONMENT'])) {
  if (isset($_SERVER['HTTP_X_SSL']) && $_SERVER['HTTP_X_SSL'] != 'ON') {
    $_SERVER['SERVER_PORT'] = 443;
  }
  else {
    $_SERVER['SERVER_PORT'] = 80;
  }
}