application.ini

pluginPaths.My_Application_Resource = "My/Application/Resource"

resources.mongodb.mappingDirs[] = APPLICATION_PATH "/../library/My/Document"

Mongodb.php

<?php

use My\Application\Container\MongoDbContainer;

/**
 * Application Resource Plugin for Doctrine MongoDB and ODM
 */
class My_Application_Resource_Mongodb extends Zend_Application_Resource_ResourceAbstract
{
    
    public function init()
    {
        $config = $this->getOptions();
        
        $this->registerAutoloaders($config);
        
        $container = new MongoDbContainer($config);
        
        Zend_Registry::set('mongodb', $container);
        
        return $container;
    }
    
    private function registerAutoloaders(array $config = array())
    {
        $autoloader = Zend_Loader_Autoloader::getInstance();
        $doctrineIncludePath = isset($config['includePath'])
            ? $config['includePath'] : APPLICATION_PATH . '/../library/Doctrine';
        
        require_once $doctrineIncludePath . '/Common/ClassLoader.php';
        
        $doctrineAutoloader = new \Doctrine\Common\ClassLoader('Doctrine');
        $autoloader->pushAutoloader(array($doctrineAutoloader, 'loadClass'), 'Doctrine');
    }
}

MongoDbContainer.php

<?php
namespace My\Application\Container;

use Doctrine\Common\Annotations\AnnotationReader,
    Doctrine\MongoDB\Connection,
    Doctrine\ODM\MongoDB\Configuration,
    Doctrine\ODM\MongoDB\Mapping\Driver\AnnotationDriver,
    Doctrine\ODM\MongoDB\DocumentManager;

/**
 * Container for Doctrine MongoDb connection and DocumentManager
 */
class MongoDbContainer
{
    /**
     * @var Connection
     */
    private $connection;
    
    /**
     * @var DocumentManager
     */
    private $documentManager;
    
    /**
     * @var Configuration
     */
    private $configuration;
    
    public function __construct(array $config = array())
    {
        $config = $this->prepareConfiguration($config);
        
        $configuration = new Configuration;
        
        $configuration->setProxyDir($config['proxy']['dir']);
        $configuration->setProxyNamespace($config['proxy']['namespace']);
        
        $configuration->setHydratorDir($config['hydrator']['dir']);
        $configuration->setHydratorNamespace($config['hydrator']['namespace']);
        
        $reader = new AnnotationReader;
        $reader->setDefaultAnnotationNamespace('Doctrine\ODM\MongoDB\Mapping\\');
        $configuration->setMetadataDriverImpl(new AnnotationDriver($reader, $config['mappingDirs']));
        
        $this->configuration = $configuration;
    }
    
    public function getConnection()
    {
        if (null === $this->connection) {
            $this->connection = new Connection();
        }
        return $this->connection;
    }
    
    public function getDocumentManager()
    {
        if (null === $this->documentManager) {
            $this->documentManager = DocumentManager::create(
                    $this->getConnection(),
                    $this->configuration
                    );
        }
        return $this->documentManager;
    }
    
    private function prepareConfiguration(array $config = array())
    {
        $defaultConfiguration = array(
            'mappingDirs' => array(),
            'proxy'       => array(
                'dir'       => \APPLICATION_PATH . '/../data/cache/Proxy',
                'namespace' => 'Proxy'
            ),
            'hydrator'    => array(
                'dir'       => \APPLICATION_PATH . '/../data/cache/Hydrator',
                'namespace' => 'Hydrator'
            )
        );
        
        return \array_replace_recursive($defaultConfiguration, $config);
    }
}