ClientWebsiteExtension.php

<?php

/*
 * This file is part of Sulu.
 *
 * (c) MASSIVE ART WebServices GmbH
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace WebsiteBundle\DependencyInjection;

use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;

/**
 * This is the class that loads and manages your bundle configuration.
 *
 * To learn more see {@link http://symfony.com/doc/current/cookbook/bundles/extension.html}
 */
class ClientWebsiteExtension extends Extension
{
    /**
     * {@inheritdoc}
     */
    public function load(array $configs, ContainerBuilder $container)
    {
        $configuration = new Configuration();
        $config = $this->processConfiguration($configuration, $configs);

        $loader = new Loader\XmlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
        $loader->load('services.xml');

        $ymlLoader = new Loader\YamlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
        $ymlLoader->load('services.yml');
    }
}

SearchIndexSubscriber.php

<?php

namespace WebsiteBundle\Subscriber;

use Massive\Bundle\SearchBundle\Search\Event\DeindexEvent;
use Massive\Bundle\SearchBundle\Search\Event\IndexEvent;
use Massive\Bundle\SearchBundle\Search\SearchEvents;
use Psr\Log\LoggerInterface;
use Sulu\Bundle\MediaBundle\Entity\Media;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

class SearchIndexSubscriber implements EventSubscriberInterface {

    /**
     * @var LoggerInterface
     */
    protected $logger;

    /**
     * @param LoggerInterface $logger
     */
    public function __construct(LoggerInterface $logger) {
        $this->logger = $logger;
    }

    /**
     * @return array
     */
    public static function getSubscribedEvents() {
        return [
            SearchEvents::INDEX => 'handleIndex',
            SearchEvents::DEINDEX => 'handleDeindex',
        ];
    }

    /**
     * @param IndexEvent $event
     */
    public function handleIndex(IndexEvent $event) {
        $this->logger->info('SEARCHINDEX');
      
        $subject = $event->getSubject();

        if ($subject instanceof Media) {
            $this->logger->info('Indexing a media element');
        }
    }

    /**
     * @param DeindexEvent $event
     */
    public function handleDeindex(DeindexEvent $event) {
        $this->logger->info('SEARCHINDEX');
      
        $subject = $event->getSubject();

        if ($subject instanceof Media) {
            $this->logger->info('Deindexing a media element');
        }
    }
}

services.yml

services:
    cloudtec.searchindexer:
        class: WebsiteBundle\Subscriber\SearchIndexSubscriber
        arguments: [ '@logger' ]
        tags:
            - { name: kernel.event_subscriber }