A sensible Docker/PHP Workflow

You can start the app like you would normally. Make requests to the server, and all the usual stuff.

docker-compose up

But if you want to do some commandline stuff

docker-compose run --user "$(id -u):$(id -g)" shell

Because home is mounted on home, all the cache fills generated by PHP are in place and you don't have to, for example, redownload the composer dependencies every time.

If you're wondering about the User stuff it's to prevent permissions errors from running things as root. This is less of an issue on OSX.

Your container/web container can be the container you use for production, without any of the development guff that sort of accrues sometimes.