It doesn't seem to include node storage, so for example you'll need to include a mysql password because if it generates a random one, you won't be able to retrieve it.
(This may have changed since last time I tried it.)
I should point out that Ansible can store passwords on the filesystem here, using the 'password' lookup plugin. So while there is no database you can still easily access things exactly like this.
(This may have changed since last time I tried it.)