title: Docker + Laravel + Composer
body: <p>I have made a docker compose file with three services web( nginx service) app(php-laravel-folder-service) database(mysal-service) for every service i create a dockerfile web.dockerfile app.dockerfile database.dockerfile.</p>
  
  <p>The problem is: in the app.dockerfile i want to install composer and execute the composer install command or php composer.phar install command and every time i got this error:  ERROR: Service 'app' failed to build: The command '/bin/sh -c composer.phar install' returned a non-zero code: 12</p>