symfony multi tenant kernel

services.yml

catalog.kernel.request_event_listener:
  class: App\CoreBundle\EventListener\KernelBootDatabaseSwitchListener
  arguments:  [@request, @doctrine.dbal.default_connection, @logger]
  scope:      request
  tags:
      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }

symfony multi tenant kernel.php

<?php
// KernelContextListener
/**
     * KernelContextListener constructor.
     * @param Request $request
     * @param Connection $connection
     * @param $logger
     */
    public function __construct(Request $request, Connection $connection, Logger $logger)
    {
        $this->request = $request;
        $this->connection = $connection;
        $this->logger = $logger;
    }
    /**
     *
     * @throws MissingSiteException
     * @throws \Doctrine\DBAL\DBALException
     */
    public function onKernelRequest()
    {
        if ($this->request->get('site')) {
            $siteId = $this->request->get('site'); // every request needs site as a param, can change to domain parsing or whatever logic
            $connection = $this->connection;
            $connectionParameters = $this->connection->getParams();
            $databaseName = sprintf("client_%d", $siteId); // here you figure out the database based on the site
            $this->logger->debug(sprintf("Switching kernel context to use database %s", $databaseName));
            $connectionParameters['dbname'] = $databaseName;
            if ($connection->isConnected()) {
                $connection->close();
            }
            // Reconstruct the DB connection and try to connect
            $connection->__construct($connectionParameters, $connection->getDriver(), $connection->getConfiguration(), $connection->getEventManager());
            $connection->connect();
            // if we can't connect, panic
            if (!$connection->isConnected()) {
                throw new ConnectionException(sprintf("Couldn't connect to database %s", $databaseName));
            }
        } else {
            throw new MissingSiteException();
        }
    }