To have xdebug working, you need to have this in your docker config for PHP.
PHP_XDEBUG: 1 PHP_XDEBUG_DEFAULT_ENABLE: 1 PHP_XDEBUG_REMOTE_CONNECT_BACK: 0 PHP_XDEBUG_REMOTE_HOST: 10.254.254.254 # macOS, Docker < 18.03
Also it is often noted that this should also be run
sudo ifconfig lo0 alias 10.254.254.254
So if your debuger is listening on 9000 port, this should work.