我想登录laravel 5.5但它无法正常工作

Question

我正在我的网站上创建一个具有注册功能的简单登录功能。注册功能正常，用户出现在数据库中。但是，登录无效。当我输入凭证时，无论是正确还是错误，但它无效。

laravel 5.5

请查看我的代码。

中间件/ Authenticates.php

我写的是否正确？

<?php
namespace App\Http\Middleware;
use Closure;
use Illuminate\Support\Facades\Auth;
class Authenticates
{
    public function handle($request, Closure $next, $guard = 'web')
    {
        if (Auth::guard($guard)->check())
        {
            return $next($request);
        }
        return redirect()->route('/');
    }
}

LoginController.php

public function getLogin()
    {
        if (Auth::guard('web')->check())
        {
            return redirect()->route('dashboard');
        }
        return view('login');
    }

路由/ web.php

Route::get('/', ['as' => '/', 'uses' => 'LoginController@getLogin']);
Route::post('/login', ['as' => 'login', 'uses' => 'LoginController@getLogin']);

Route::group(['middleware', ['authenticates', 'roles']], function (){
    Route::get('/logout', ['as' => 'logout', 'uses' => 'LoginController@getLogout']);
    Route::get('/dashboard', ['as' => 'dashboard', 'uses' => 'DashboardController@dashboard']);
});

login.blade.php

<form class="login-form" action="{{ route('login') }}" method="post">
        {!! csrf_field() !!}
        <div class="login-wrap">
            <p class="login-img"><i class="icon_lock_alt"></i></p>
            <div class="input-group">
                <span class="input-group-addon"><i class="icon_profile"></i></span>
                <input type="text" name="username" class="form-control" placeholder="Username" autofocus>
            </div>
            <div class="input-group">
                <span class="input-group-addon"><i class="icon_key_alt"></i></span>
                <input type="password" name="password" class="form-control" placeholder="Password">
            </div>
            <label class="checkbox">
                <input type="checkbox" value="remember-me"> Remember me
                <span class="pull-right"> <a href="#"> Forgot Password?</a></span>
            </label>
            <button class="btn btn-primary btn-lg btn-block" type="submit">Login</button>
            <button class="btn btn-info btn-lg btn-block" type="reset">Reset</button>
        </div>
    </form>