nginx and PHP-FPM both need access to the files--at the same location. It's thus not easy to have a single nginx serving multiple PHP-FPM containers. You always need a webserver in the same container as PHP-FPM.
* [WP multisite + Caddy](https://skippy.net/caddy-docker-php-wordpress): arguments against using the Wordpress Docker image, keeps the whole wp install outside the image, and instead focuses on properly configuring PHP-FPM. Has the advantage of being reusable for other PHP projects. Is well argumented. Tackles file access rights and mailing (ssmtp), it's a good source!
