php - Symfony: change database dynamically

Question

let's say I have 3 databases:

• prefix_db1
• prefix_db2
• prefix_db3
  

And I want to connect to them dynamically from the url like this http://localhost/my-project/web/app_dev.php/db1/books so I know which database to conenct to from the url (in this case prefix_db1)
And basically the idea was to prepare a listener that will be fired with each http request, get the database name from the url and then override doctrin's params, something like this:
Within services.yml:

dynamic_connection:
        class: AppBundleserviceDynamicDBConnector
        arguments:  ['@request_stack']
        calls:
            - [ setDoctrineConnection, ['@doctrine.dbal.default_connection'] ]
        tags:
            - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }

My listener:

<?php    
namespace AppBundleservice;

use DoctrineDBALConnection;
use SymfonyComponentHttpFoundationRequestStack;
use Exception;

class DynamicDBConnector
{
    /**
     * @var Connection
     */
    private $connection;

    /*
     * @var Request
     */
    private $request;


    public function __construct(RequestStack $requestStack)
    {
        $this->request = $requestStack->getCurrentRequest();

    }

    /**
     * Sets the DB Name prefix to use when selecting the database to connect to
     *
     * @param  Connection       $connection
     * @return DynamicDBConnector $this
     */
    public function setDoctrineConnection(Connection $connection)
    {
        $this->connection = $connection;
        return $this;
    }

    public function onKernelRequest()
    {
        if ($this->request->attributes->has('_company')) {

            $connection = $this->connection;
            $params     = $this->connection->getParams();

            $companyName = $this->request->get('_company');
            // I did the concatenation here because in paramaters.yml I just put the prefix (database_name: prefix_) so after the concatenation I get the whole database name "prefix_db1"
            $params['dbname'] = $params['dbname'] . $companyName;

            // Set up the parameters for the parent
            $connection->__construct(
                $params,
                $connection->getDriver(),
                $connection->getConfiguration(),
                $connection->getEventManager()
            );

            try {
                $connection->connect();
            } catch (Exception $e) {
                // log and handle exception
            }
        }

        return $this;
    }
}

Now this worked very well I have tested it using a simple list of books and each time I change the url I get the list related to each database:

http://localhost/my-project/web/app_dev.php/db1/books // I get books of database prefix_db1

http://localhost/my-project/web/app_dev.php/db2/books // I get books of database prefix_db2

Now let's get to the problem shall we :):
The problem now is that when I secure my project with authentication system and try to login (of course each database has user table) using this url http://localhost/my-project/web/app_dev.php/db1/login I get this exception :

An exception occured in driver: SQLSTATE[HY000] [1049] Base 'prefix_' unknown

As you can see symfony tried to login the user using the database_name declared in parameters.yml which means that the security_checker of symfony has been fired before my listener and before overriding Doctrine's params.

My question:
Is there any way to fire my listener before any other http request listener ? or maybe an alternative solution to make sure that any request to database must be with the right database name.
Sorry for the long post.

EDIT:
From the official documentation of symfony:
https://symfony.com/doc/2.3/cookbook/event_dispatcher/event_listener.html

The other optional tag attribute is called priority, which defaults to 0 and it controls the order in which listeners are executed (the highest the priority, the earlier a listener is executed). This is useful when you need to guarantee that one listener is executed before another. The priorities of the internal Symfony listeners usually range from -255 to 255 but your own listeners can use any positive or negative integer.

I set the priority of my listener to 10000:

tags:
    - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: 10000 }

But the problem persist, still can't fire my listener before symfony!

Answer 1

I found a solution
The idea is tochange the default Connection class that symfony uses to create a database connection:

doctrine:
    dbal:
        connections:
            default:
                wrapper_class: AppBundleDoctrineDynamicConnection
                driver: pdo_mysql
                host: '%database_host%'
                port: '%database_port%'
                dbname: '%database_name%'
                user: '%database_user%'
                password: '%database_password%'
                charset: UTF8

After that we can change the given params in the constructor:

use DoctrineDBALConnection;
use DoctrineDBALDriver;

class DynamicConnection extends Connection
{
    public function __construct(array $params, Driver $driver, $config, $eventManager)
    {
        $params['dbname'] = 'teqsdqsdqst';
        parent::__construct($params, $driver, $config, $eventManager);
    }
}

Now we just need to get the parameter from the url and set inside $params['dbname'].
In this way we make sure that symfony will always use this class to create the connection and we no longer need to fire listeners with http requestes