disable-newrelic-at-amp.php

<?php
/**
 * Plugin Name: Disable NewRelic at AMP
 * Description: Removes NewRelic script code from AMP pages
 * Plugin URI:  http://www.lars-schenk.com/
 * Version:     0.0.2
 * Author:      Lars Schenk
 * Author URI:  http://www.lars-schenk.com
 * Licence:     MIT
 * License URI: http://opensource.org/licenses/MIT
 * 
 * Synopsis:
 * Disable NewRelic when AMP pages are served.
 * This works only when pages will not be served via advanced cache.
 * When advanced cache is serving the page, no hooks will be fired and
 * no plugins will be loaded. Not even mu-plugins.
 * 
 * So we have to disable the extension in the advanced cache.  
 * See 
 * https://github.com/petermolnar/wp-ffpc/pull/47
 */

add_action('muplugins_loaded', 'disable_newrelic_at_amp');

function disable_newrelic_at_amp()
{
    if (stripos($_SERVER["REQUEST_URI"], '/amp/')) {
        if (extension_loaded('newrelic')) {
            newrelic_disable_autorum();
        }
    }
}