Docker >=1.9 networking

I am trying to find out how new docker networking is working. I am pretty new in docker so sorry if this is dumo question, but here it comes:

  • I want to have web frontend that has public ip in http and https.
  • I want to have some docker containers running web services like drupal7 and another container for drupal8
  • I need one container for mariadb
    Is is right idea, if I’ll create one network for database traffic and join all three containers to that, then I’ll create second network where web frontend (nginx, haproxy etc) and all web containers are running?
    Do I then define redirections from frontent to backends with names network.container_name?
    Can this be automatized in a way, that all new containers in web network would be added into forwarding list automatically?