ElasticaClientFactory.php

<?php
namespace User\Service;

use Zend\ServiceManager\FactoryInterface;
use Zend\ServiceManager\ServiceLocatorInterface;

class ElasticaClientFactory implements FactoryInterface
{
    public function createService(ServiceLocatorInterface $sl)
    {
        $config = $sl->get('Configuration');
        $clientOptions = isset($config['elastica']) ? $config['elastica'] : array();
        $client = new \Elastica\Client($clientOptions);

        return $client;
    }
}

module.config.php

<?php
namespace User;

return array(
    'controllers' => array(
        'invokables' => array(
            'User\Controller\User' => 'User\Controller\UserController',
        ),
    ),
    'router' => array(
        'routes' => array(
            'user' => array(
                'type'    => 'segment',
                'options' => array(
                    'route'    => '/user[/][:action][/:id]',
                    'constraints' => array(
                        'action' => '[a-zA-Z][a-zA-Z0-9_-]*',
                        'id'     => '[0-9]+',
                    ),
                    'defaults' => array(
                        'controller' => 'User\Controller\User',
                        'action'     => 'index',
                    ),
                ),
            ),
        ),
    ),
    'view_manager' => array(
        'template_path_stack' => array(
            'user' => __DIR__ . '/../view',
        ),
    ),
    'doctrine' => array(
        'driver' => array(
            __NAMESPACE__ . '_driver' => array(
                'class' => 'Doctrine\ORM\Mapping\Driver\AnnotationDriver',
                'cache' => 'array',
                'paths' => array(__DIR__ . '/../src/' . __NAMESPACE__ . '/Entity')
            ),
            'orm_default' => array(
                'drivers' => array(
                    __NAMESPACE__ . '\Entity' => __NAMESPACE__ . '_driver'
                )
            )
        )
    ),
    
    'elastica' => array(
        'servers' => array(
            array('host' => '127.0.0.1','port' => 9200),
            // You can add more servers when necessary
            // array('host' => '127.0.0.1','port' => 9200)
        ),
    ),

    'service_manager' => array(
        'factories' => array(
            'elastica-client' => 'User\Service\ElasticaClientFactory'
        ),
    )
);