Pantheon Quicksilver task to enable and disable modules on Database copy.

update_modules.php

<?php
/**
 * Enable and disable modules based on settings in $conf['qs_module_settings']
 */

// Without resorting to fixed paths, this is the easiest way to get the data from the settings file and into this script.
$module_settings = json_decode(shell_exec("drush vget qs_module_settings --exact --format=json"));
$module_list = shell_exec("drush pm-list --status=enabled --pipe 2>&1");
$enabled_modules = explode("\n", $module_list);
$module_list = shell_exec("drush pm-list --status=disabled --pipe 2>&1");
$disabled_modules = explode("\n", $module_list);

if(!$module_settings || !$enabled_modules || !$disabled_modules)
  return;

foreach($module_settings->enabled as $module) {
  if(in_array($module, $disabled_modules)) {
    passthru("drush pm-enable -y $module");
  }
}

foreach($module_settings->disabled as $module) {
  if(in_array($module, $enabled_modules)) {
    passthru("drush pm-disable -y $module");
  }
}