Dynamic env-files (multiple databases) and artisan commands - laravel

Question

I have a large project which will have each customer on their own separate database. To get this to work we use a custom .env-loader that loads each customers .envby checking the customers subdomain (unique to each customer).
However, of course this doesn't work with artisan commands. For instance, when I want to migrate, I will need to migrate all databases at once. So I've set up an Artisan command that fetches the .env-files and loop through them and then calls the default artisan migrate. But it is not working as expected.
I've tried everything; for instance:
$dotenv = new Dotenv('/env', '.test.env');
$dotenv->overload();
And:
app()->useEnvironmentPath('/env');
app()->loadEnvironmentFrom('.test.env');
And even:
config('database.connections.mysql.database', 'test_database');
As soon as I run $this->call('migrate'); the app defaults to the default .env and ignores all customizations at runtime. Does anyone have an idea on how I can overload the migration commands choice of database?
Note: I know that I can manually setup multiple connections in config/database.php (for instance like: Overriding Default Laravel database configuration for artisan migrate commands), however, image a few dozen customers and this would not be viable.

Answer 1

I had to do something similar with SQLite database that were being created by the console commands, and the only way I could get the migrations to run was by creating a database config on the fly:
Config::set('database.connections.'.$config_key, array(
'driver' => 'sqlite',
'database' => storage_path($database_name),
'prefix' => '',
));
And then I would call the migrate command:
Artisan::call('migrate', [
'--database' => $config_key,
'--path' => 'database/offline/'.$type.'/migrations',
]);

Answer 2

After a whole lot of issues I was able to sort it this way;
In Laravel 5 there seem to be a difference in Config::set(), config('config',['key' => 'value]) and config()-set('config', ['key' => 'value']).
After a lot of testing different variant we managed to get a solution this way;
$connection = 'connection';
$iterator = 0;
foreach ($files as $file) {
App::useEnvironmentPath('/env');
App::loadEnvironmentFrom('.file.env');
// Create a new connection "on the fly"
config()->set('database.connections.' . $connection . '_' . $iterator, [
'driver' => 'mysql',
'host' => env('DB_HOST'),
'database' => env('DB_DATABASE'),
'username' => env('DB_USERNAME'),
'password' => env('DB_PASSWORD'),
'charset' => 'utf8',
'collation' => 'utf8_unicode_ci',
'prefix' => '',
'strict' => false,
]);
// Call regular migration command
$this->call('migrate', ['--force' => true, '--database' => $connection . '_' . $iterator]);
$iterator++;
}
This manages to set multiple new connections to the MySQL-database, and then seed each one of them.
Thanks to #David Allen here for the inspiration.