@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
Should new Piwigo users be created when users authenticate succesfully via LDAP?
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.