githook/app/controllers/IndexController.php

<?php
declare(strict_types=1);

class IndexController extends ControllerBase
{

    public function indexAction()
    {

	if(!$this->request->isPost()) exit();

        if(isset($_POST['payload']) && $_POST['payload']){
          $payload = json_decode($_POST['payload'],true);
          $name = $payload['repository']['name'];

          if(is_dir('/home/www/'.$name)){
              system('cd /home/www/'.$name.';git pull',$return);
            }else{
              $repo = $payload['repository']['ssh_url'];
              system('cd /home/www;git clone '.$repo.';git pull',$return);
            }

            return '请求成功';
        }
        return '请求错误';
    }

    public function show404Action(){
        return 'UNKNOWN REQUEST';
    }

}