Symfony2 using second database while testing

Im using behat for testing in my symfony2 aplication. Right now I need to have two databases. First (which is working right now), for normal use, like user doing something on site. Second database (which exists and behat work on it), for tests purpose.

What I got now is two working databases, and behat. Behat use second database, but problem is that while tests flow, site doesnt use it.

My config.yml:

doctrine:
    dbal:
        driver:   pdo_mysql
        host:     "%database_host%"
        port:     "%database_port%"
        dbname:   "%database_name%"
        user:     "%database_user%"
        password: "%database_password%"
        charset:  UTF8

My config_test.yml:

doctrine:
    dbal:
        dbname:   "%database_name%_test"

My 'behat.yml':

default:
suites:
    default:
        paths:
            features: '%paths.base%/features'
            bootstrap:  '%paths.base%/features/bootstrap'
        contexts:
            - FeatureContext: ~
            - EwidencjaContext:
                userManager: '@fos_user.user_manager'
                em: '@doctrine.orm.entity_manager'
                packageManager: '@em.package_manager'
extensions:
    Behat\Symfony2Extension: ~
    Behat\MinkExtension:
        base_url:  http://my_nginx/app_test.php
        goutte: ~
        selenium2:
            browser: "chrome"
            wd_host: http://selenium_chrome:4444/wd/hub
            capabilities: { "browserName": "chrome", "browser": "chrome"}
    Bex\Behat\ScreenshotExtension:
        image_drivers:
            local:
                screenshot_directory: tests/features/images/
                clear_screenshot_directory: true

What can I do to change database for time tests are in progress?

Solution

This uses SQLite for Behat (test) environment but you can use MySQL if you want to.

config_test.yml

doctrine:
    dbal:
        connections:
            default:
                driver: pdo_sqlite
                path: %kernel.cache_dir%/default.db
                charset: UTF8

app_test.php

The relevant line should be: $kernel = new AppKernel('test', true);

AppKernel.php

The relevant line should be: if (in_array($this->getEnvironment(), ['dev', 'test'])) {

behat.yml

Pay attention to app_test.php.

default:
    extensions:
        Behat\Symfony2Extension: ~
        Behat\MinkExtension:
            base_url: http://your_app_domain.dev/app_test.php
        ...
        ...
        ...

Virtual hosts settings:

<VirtualHost *:80>
   ServerName your_app_domain.dev
   DocumentRoot "/path/to/your/app/web"

   <Directory "/path/to/your/app/web">
       Options Indexes FollowSymlinks
       AllowOverride All
       Order allow,deny
       Allow from all
   </Directory>

   ErrorLog ${APACHE_LOG_DIR}/your_app_domain.dev.error.log
   CustomLog ${APACHE_LOG_DIR}/your_app_domain.dev.access.log combined
</VirtualHost>

Some information:

Outcome:

If you call http://your_app_domain.dev/app_dev.php it will use default DB settings in config but if you call http://your_app_domain.dev/app_test.php then it will use config_test settings.