http://localhost:8080/Extranet/login

{
  "userName": "Painkiller",
  "email": "painkiller@gmail.com",
  "enabled": true
}

<?php

namespace AppAuthentication;

use IlluminateAuthGenericUser;
use IlluminateContractsAuthAuthenticatable;
use IlluminateContractsAuthUserProvider as IlluminateUserProvider;
use GuzzleHttpClient;
use function GuzzleHttpjson_encode;
use function GuzzleHttpjson_decode;
use IlluminateSupportFacadesAuth;
use IlluminateSupportFacadesLog;

class UserProvider implements IlluminateUserProvider
{
    public function retrieveById($identifier)
    {
        // TODO: Implement retrieveById() method.
        Log::info('retrieveById START');

        $user = Session::get('loggedUser');

        //$user = Auth::user();

        return $user;

    }

    public function retrieveByToken($identifier, $token)
    {
        // TODO: Implement retrieveByToken() method.
        Log::info('retrieveByToken START');
    }

    public function updateRememberToken(Authenticatable $user, $token)
    {
        // TODO: Implement updateRememberToken() method.
        Log::info('updateRememberToken START');
    }

    public function retrieveByCredentials(array $credentials) {

        // TODO: Implement retrieveByCredentials() method.

        Log::info('retrieveByCredentials START');
        Log::info('INSERTED USER CREDENTIAL: '.$credentials['email'] . ' ' .$credentials['password']);

        $client = new Client(); //GuzzleHttpClient

        $response = $client->get('http://localhost:8080/Extranet/login',
            [
                'auth' => [
                    'nobili.andrea@gmail.com',
                    'pswd'
                ]
            ]);

        $dettagliLogin = json_decode($response->getBody());

        Log::info('response: '.(json_encode($dettagliLogin)));

        //$user = new User('Pippo', 'pippo@google.com', true);

        $attributes = array(
            'id' => 123,
            'username' => 'nobili.andrea@gmail.com',
            'password' => Hash::make('SuperSecret'),
            'name' => 'Dummy User',
        );

        $user = new GenericUser($attributes);

        Log::info('USER: '.(json_encode($user)));

        Session::set('loggedUser', $user);

        return $user;


    }

    public function validateCredentials(Authenticatable $user, array $credentials)
    {
        // TODO: Implement validateCredentials() method.
        Log::info('validateCredentials START');
        return true;
    }

}

public function retrieveByCredentials(array $credentials) {

    // TODO: Implement retrieveByCredentials() method.

    Log::info('retrieveByCredentials START');
    Log::info('INSERTED USER CREDENTIAL: '.$credentials['email'] . ' ' .$credentials['password']);

    $client = new Client(); //GuzzleHttpClient

    $response = $client->get('http://localhost:8080/Extranet/login',
        [
            'auth' => [
                'nobili.andrea@gmail.com',
                'pswd'
            ]
        ]);

    $dettagliLogin = json_decode($response->getBody());

    Log::info('response: '.(json_encode($dettagliLogin)));

    //$user = new User('Pippo', 'pippo@google.com', true);

    $attributes = array(
        'id' => 123,
        'username' => 'nobili.andrea@gmail.com',
        'password' => Hash::make('SuperSecret'),
        'name' => 'Dummy User',
    );

    $user = new GenericUser($attributes);

    Log::info('USER: '.(json_encode($user)));

    Session::set('loggedUser', $user);

    return $user;

}

Session::set('loggedUser', $user);

public function retrieveById($identifier)
{
    // TODO: Implement retrieveById() method.
    Log::info('retrieveById START');

    $user = Session::get('loggedUser');

    //$user = Auth::user();

    return $user;

}

Session::set('loggedUser', $user);

$user = Session::get('loggedUser');