Independent services: web, mysql

[rnoxy]

Could anyone explain the docker-compose.yml file?

There are two services: web and mysql.
However, the first one (web) seems to not depend on any service.

For example, how do you pass the MYSQL_ROOT_PASSWORD or MYSQL_PASSWORD to the web service?

see https://github.com/terrestris/projectsend-docker/blob/76811666b49d71d1c13472753f5456a069123c2c/docker-compose.yml#L11C3-L20C34