4 May 2018
https://www.lullabot.com/articles/goodbye-drush-make-hello-composer
este é melhor: https://www.lullabot.com/articles/drupal-8-composer-best-practices
bad gateway
https://www.datadoghq.com/blog/nginx-502-bad-gateway-errors-php-fpm/
para instalar o composer https://xana.freeddns.org/content/instalar-o-composer-no-debian-buster.
depois instalar ainda:
sudo apt install php-xml php-curl php-gd php-mbstring
verificar extensões php necessárias:
composer check-platform-reqs