As per an old issue: https://www.virtualmin.com/node/14248
I have configured LDAP and it's all working. The problem is when I try to use Webmin's LDAP Users and Groups module. Even with the module fully setup, the LDAP Client and Server modules are showing up great, but the Users and Groups won't show up as "installed" unless I manually adjust the /etc/webmin/installed.cache and set ldap-useradmin=1.
What could be causing this to not be working as expected and always be removed from the installed list even though it's there, it's fully functional, etc?
I have found part of the problem.
In the install_check.pl for ldap-useradmin, I started putting debug prints, and one of them was to print the $config{'auth_ldap'}, which pointed to /etc/libnss-ldap.conf.
Where is it getting this value from? My LDAP Client setup uses /etc/ldap.conf which exists and does work. It's a combined libnss-ldap.conf and libpam-ldap.conf as one file, as per how Ubuntu 10.04 uses it, and I believe even Ubuntu 8.04 did as well (though, I am not certain if that's true for 8.04).
Anyway. That alone is what's causing the LDAP Users and Groups module to not detect as being "installed" and "configured", to the modules check. Temporary fix, I symlinked /etc/libnss-ldap.conf to point to /etc/ldap.conf, and now it's working fine with the install check.
This seems to me like a potential bug.