laravel-blog/app/Http/Controllers/Auth/Admin/LoginController.php

<?php

namespace App\Http\Controllers\Auth\Admin;

use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class LoginController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Login Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles authenticating users for the application and
    | redirecting them to your home screen. The controller uses a trait
    | to conveniently provide its functionality to your applications.
    |
    */

    use AuthenticatesUsers;

    /**
     * Where to redirect users after login.
     *
     * @var string
     */
    protected $redirectTo = '/admin';

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest:admin')->except('logout');
    }

    /**
     * Get the guard to be used during authentication.
     *
     * @return \Illuminate\Contracts\Auth\StatefulGuard
     */
    protected function guard()
    {
        return Auth::guard('admin');
    }

    /**
     * Get the guard to be used during authentication.
     *
     * @return \Illuminate\Contracts\Auth\StatefulGuard
     */

    public function showAdminLoginForm()
    {
        return view('admin.auth.login', ['guard' => 'admin']);
    }

    public function login(Request $request)
    {
        $this->validate($request, [
            'email' => 'required|email',
            'password' => 'required'
        ]);

        if (Auth::guard('admin')->attempt(['email' => $request->email, 'password' => $request->password], $request->get('remember'))) {

            return redirect()->intended('/admin');
        }
        return back()->withInput($request->only('email', 'remember'))->withErrors(['password' => 'Invalid account or password.']);
    }

    public function logout(Request $request)
    {
        $this->guard()->logout();

        $request->session()->forget($this->guard()->getName());

        $request->session()->regenerate();

        return redirect('/admin');
    }

}