Choose database at login

Here is a concept that might help you.

https://divinglaravel.com/understanding-how-laravel-configures-database-connections

However, you have to pass the database each time you make a request

Thanks, but my problem is not to work with multiple database at the same time , but choose one among many at runtime and more precisely at login

From what i understand this is possible by using something like : Config::set('database.connections.mysql.database', 'DB_SELECTED_AT_LOGIN'); 1- Is this correct ?

It should work, provided a database with a matching name actually exists on the server. I think you could set this in the controller login method after you've authenticated the user.

2- If so, is it mandatory to completely rewrite the LoginController

You won't need to completely rewrite the default Laravel LoginController for this; you can just modify it to accept a database_name variable. Which leads to another question -- are you going to be hard-coding the list of database options in your login form OR is it going to be a list generated by the application? If it's the latter, then I think you have some decisions to make about where that data is going to come from and you may need another route + controller method to fetch that list of databases, or the login view needs to be passed that list of databases.

3- once i manage to get the parameter containing the db name how do i persist this setting during the user session ?

The middleware solution you mentioned could work for this, but I get that you need a reference to which database was selected. Perhaps using session variables in combination with middleware could work for you... https://laravel.com/docs/6.x/session#storing-data

My answers are based on the limited information about the structure of your application. If I had more details, I may be able to help in more detail.

Have a nice day

@grunk what about:

View (add new field):

<div class="form-group row">
    <label for="database" class="col-md-4 col-form-label text-md-right">{{ __('Database') }}</label>

    <div class="col-md-6">
        <select name="database" class="form-control @error('database') is-invalid @enderror" required>
            <option {{ old('database') === 'db1' ? 'selected' : '' }} value="db1">DB1</option>
            <option {{ old('database') ===  'db2' ? 'selected' : '' }} value="db2">DB2</option>
        </select>

        @error('database')
            <span class="invalid-feedback" role="alert">
                <strong>{{ $message }}</strong>
            </span>
        @enderror
    </div>
</div>

LoginController:

class LoginController extends Controller
{
    use AuthenticatesUsers {
        attemptLogin as baseAttemptLogin;
    }

    protected $redirectTo = RouteServiceProvider::HOME;

  
    protected function attemptLogin(Request $request)
    {
        config(['database.connections.mysql.database' => $request->database]);
        
        return $this->baseAttemptLogin($request);
    }

    protected function authenticated(Request $request, $user)
    {
        session(['database' => $request->database]);
    }

   protected function validateLogin(Request $request)
   {
      $request->validate([
         'database' => [
            'required',
            Rule::in(['db1', 'db2']),
         ],
         $this->username() => 'required|string',
         'password' => 'required|string',
      ]);
   }
}

app\Http\Kernel.php:

protected $middlewareGroups = [
    'web' => [
       //...
        \Illuminate\Session\Middleware\StartSession::class,
        \App\Http\Middleware\SetDBConnection::class,
        \Illuminate\View\Middleware\ShareErrorsFromSession::class,
        //...
    ],

    /...
];

app/Http/Middleware/SetDBConnection.php:

namespace App\Http\Middleware;

use Closure;

class SetDBConnection
{
    public function handle($request, Closure $next)
    {
        if (session('database')) {
            config(['database.connections.mysql.database' => session('database')]);
        }

        return $next($request);
    }
}

Thanks guys for your answers. @sti3bas i'll try this tomorrow. it's how i imagined it but didn't know how to implement it the laravel way. Thanks

Seems like this has already been answered but I just want to confirm that yes you can indeed set up and/or reconfigure connections at runtime. In my own project I did it like this:

$dynamicConnection = [ 'driver' => 'mysql', 'host' => '127.0.0.1', ...]
config(['database.connections.dynamic' => $dynamicConnection]);
DB::purge('dynamic');

Just a few things I discovered:

DB::purge is important.

You can use middleware to inject the connection info at runtime, which is what I did. You could also potentially do it in a service provider.

Check out config/database.php to see what connection is default. If you update the default connection, everything will just work. But if your dynamic connection is not default, you will have to manually reference it in your models and queries.

For models, just add protected $connection = 'dynamic'

For queries, use DB::connection('dynamic')->select(...)

Good luck!

i just tested @sti3bas solution and it's working perfectly. Thank you very much. I just need to apply some modification to the password restoration process to handle the correct database and i'm good to go.