Laravel testing with mutliple databases in memory

I like setup my testing suite in laravel app with two (2) database connections. Also for questions with Gitlab, I need a configuration that allows me to indicate to gitlab, that when doing the tests use a single database, instead of the two, due to the difficulty of creating a docker with more than one database in mysql.

Config/database

<?php

use Illuminate\Support\Str;

return [
   'default' => env('DB_CONNECTION', 'mysql'),
   'connection_vmail' => env('DB_CONNECTION_VMAIL', 'vmail'),

    'mysql' => [
        'driver' => 'mysql',
        'url' => env('DATABASE_URL'),
        'host' => env('DB_HOST', '127.0.0.1'),
        'port' => env('DB_PORT', '3306'),
        'database' => env('DB_DATABASE', 'forge'),
        'username' => env('DB_USERNAME', 'forge'),
        'password' => env('DB_PASSWORD', ''),
        'unix_socket' => env('DB_SOCKET', ''),
        'charset' => 'utf8mb4',
        'collation' => 'utf8mb4_unicode_ci',
        'prefix' => env('DB_PREFIX', ''),
        'prefix_indexes' => true,
        'strict' => true,
        'engine' => null,
        'options' => extension_loaded('pdo_mysql') ? array_filter([
            PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
        ]) : [],
    ],

    'mysql_vmail' => [
        'driver' => 'mysql',
        'url' => env('DATABASE_URL'),
        'host' => env('DB_HOST', '127.0.0.1'),
        'port' => env('DB_PORT', '3306'),
        'database' => env('DB_DATABASE_VMAIL', 'forge'),
        'username' => env('DB_USERNAME_VMAIL', 'forge'),
        'password' => env('DB_PASSWORD_VMAIL', ''),
        'unix_socket' => env('DB_SOCKET', ''),
        'charset' => 'utf8mb4',
        'collation' => 'utf8mb4_unicode_ci',
        'prefix' => env('DB_PREFIX_VMAIL', ''),
        'prefix_indexes' => true,
        'strict' => true,
        'engine' => null,
        'options' => extension_loaded('pdo_mysql') ? array_filter([
            PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
        ]) : [],
    ],

        // PHPunit testing main connection
    'testing' => [
        'driver' => 'sqlite',
        'database' => ':memory:',
        'prefix' => 'albarid_',
        'foreign_key_constraints' => env('DB_FOREIGN_KEYS', true),
    ],
    // PHPunit testing audit connection
    'testing_vmail' => [
        'driver' => 'sqlite',
        'database' => ':memory:',
        'prefix' => 'vmail_',
        'foreign_key_constraints' => env('DB_FOREIGN_KEYS', true),
    ],

.env

APP_ENV=local

DB_CONNECTION=mysql
DB_HOST=IP_MYSQL
DB_PORT=3306
DB_DATABASE=albarid
DB_USERNAME=albarid
DB_PASSWORD=MyPass>Word
DB_PREFIX=

DB_CONNECTION_VMAIL=mysql_vmail
DB_HOST_VMAIL=IP_VMAIL
DB_PORT_VMAIL=3306
DB_DATABASE_VMAIL=vmail
DB_USERNAME_VMAIL=albarid
DB_PASSWORD_VMAIL=MyPass>Word
DB_PREFIX_VMAIL=

phpunit.xml

<php>
    <server name="APP_ENV" value="testing"/>
    <server name="DB_CONNECTION" value="testing"/>
    <server name="DB_CONNECTION_VMAIL" value="testing_vmail" />
    ...
</php>

Model MyTable

protected $table = 'mytable';
protected $connection = 'mysql_vmail';

Well, if work with DB::table('mytable') work fine and all test write in memory, but if try use factories, write in normal connection.