By default you can just use ports to get at the different services, in edxapp/vars/main.yml:

```
lms_xml_nginx_port: 18030
lms_nginx_port: 80
lms_preview_nginx_port: 18020
cms_nginx_port: 18010
```

So to access the cms after running this playbook on vagrant or an aws instance, http://host:18010

If you override the cms port so that it's port 80 (which is what we are doing for studio.sandbox.edx.org) it will also do a dns match for studio.*.  Seemed generic enough but I'm open to changes.