app.php

<?php
require_once __DIR__.'/../vendor/autoload.php'; 
require_once __DIR__.'/boot.php'; 

use Silex\Application;
use Symfony\Component\HttpFoundation\Request;
use Synfony\Component\HttpFoundation\Response;

$app = new Application();

$app->get('/', function() use ($app, $em) {
    
    $post = new App\Model\Post();
    $post->setBody('test');
    $post->setTitle('test');

    $em->persist($post);
    $em->flush();
    
    return 'home page' ;
});

$app->get('/all', function() use ($app, $em) {
    
    $posts = $em->getRepository('App\Model\Post')->findAll();
    
    ob_start();
    print_r($posts);
    $content = ob_get_contents();
    ob_end_clean();
    
    return $content;
});


return $app;

boot.php

<?php
use Doctrine\ORM\Tools\Setup,
    Doctrine\ORM\EntityManager,
    Doctrine\Common\EventManager as EventManager,
    Doctrine\ORM\Events,
    Doctrine\ORM\Configuration,
    Doctrine\Common\Cache\ArrayCache as Cache,
    Doctrine\Common\Annotations\AnnotationRegistry, 
    Doctrine\Common\Annotations\AnnotationReader,
    Doctrine\Common\ClassLoader;;
    
$loader = require __DIR__.'/../vendor/autoload.php';
$loader->add('App', __DIR__.'/');

//doctrine
$config = new Configuration();
$config->setProxyDir('/tmp');
$config->setProxyNamespace('EntityProxy');
$config->setAutoGenerateProxyClasses(true);

AnnotationRegistry::registerFile(__DIR__. '/../vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/Driver/DoctrineAnnotations.php');

$driver = new Doctrine\ORM\Mapping\Driver\AnnotationDriver(
    new Doctrine\Common\Annotations\AnnotationReader(),
    array(__DIR__ )
);
$config->setMetadataDriverImpl($driver);

//getting the EntityManager
$em = EntityManager::create(
    array(
        'driver'  => 'pdo_mysql',
        'host'    => 'localhost',
        'port'    => '3306',
        'user'    => 'root',
        'password'  => 'password',
        'dbname'  => 'silex',
    ),
    $config
);