Example usage of Socialite with one Controller in Laravel

services.php

<?php
return = [
'google' => [
        'client_id' => env('GOOGLE_CLIENT_ID'),
        'client_secret' => env('GOOGLE_CLIENT_SECRET'),
        'redirect' => env('GOOGLE_CALLBACK_URL'),
    ],

    'facebook' => [
        'client_id' => env('FACEBOOK_CLIENT_ID'),
        'client_secret' =>  env('FACEBOOK_CLIENT_SECRET'),
        'redirect' =>  env('FACEBOOK_CALLBACK_URL'),
    ],

    'github' => [
        'client_id' => env('GITHUB_CLIENT_ID'),
        'client_secret' => env('GITHUB_CLIENT_SECRET'),
        'redirect' => env('GITHUB_CALLBACK_URL'),
    ],
 ];

SocialController.php

<?php

namespace App\Http\Controllers;

use App\Traits\SocialUsers;
use Illuminate\Http\Request;
use Laravel\Socialite\Facades\Socialite;

class SocialController extends Controller
{
    use SocialUsers;

    /**
     * Redirect the user to the Google authentication page.
     *
     * @param Request $request
     * @param $provider
     * @return Response
     */
    public function redirectToProvider(Request $request, $provider)
    {
        return Socialite::driver($provider)->redirect();
    }

    /**
     * Obtain the user information from Google.
     *
     * @param Request $request
     * @param $provider
     * @return Response
     */
    public function handleProviderCallback(Request $request, $provider)
    {
        $user = Socialite::driver($provider)->user();
        return $this->checkUser($user, $provider);
    }

    public function logout()
    {
        return $this->userLogout();
    }
}

SocialUsers.php

<?php

namespace App\Traits;

use App\User;

trait SocialUsers
{
    private function getUserImage($user, $provider)
    {
        if ($provider == "google") {
            return $user->getAvatar()."0";
        }

        return $user->avatar;
    }

    public function checkUser($socialiteUser, $provider)
    {
        $user = User::where('email', $socialiteUser->email)->first();
        if (!$user) {
            return redirect()->route('login')->withErrors(\Lang::get('auth.user_not_registered'));
        } else {
            // update details
            $user->profile_image_path = $this->getUserImage($socialiteUser, $provider);
            $user->save();

            \Auth::login($user); // manually authorize the user

            return redirect()->route('dashboard'); // redirect to home page
        }
    }

    public function userLogout()
    {
        session()->flush();
        \Auth::logout();

        return redirect('/');
    }
}

web.php

Route::prefix('auth')->group(function () {
    Route::get('provider/{provider}', 'SocialController@redirectToProvider')->name('social.login');
    Route::get('provider/{provider}/callback', 'SocialController@handleProviderCallback');
});

great, but you missed the config and .env files example.