@alexy here it goes:
install an empty lamp app
install piwigo (download from http://piwigo.org/download/dlcounter.php?code=latest)
following this tutorial http://www.jouvinio.net/wiki/index.php/LDAP_Plugin_Piwigo and put https://github.com/kvakanet/ldap_login/archive/config2base.zip as ldap_login in your plugins directory and activate it in the backend
add the following info in the "Ldap Login" settings:
LDAP server host: 172.18.0.1
LDAP port: 3002
BASE DN of LDAP server: ou=users,dc=cloudron
Users Branch: ou=users
LDAP attributes: ou=users,dc=cloudron
Attribute corresponding to the user name: username
Groups Branch: ou=groups,dc=cloudron
Attributes corresponding to the group name: cn
Admins group: users (not working)
In the "New users when LDAP auth is successful" tab check
Automatic group settings don't work, maybe that's my fault, this means after a user is successfully logged in, you have to manually change his/her group to whichever you want. There's also the mentioning of an OpenLDAP bug on the page, but that's where my french stopped working and I didn't use that code.
Let me know how it goes.