user/password Authentication via Joomla database

[Graham S. Jarvis]

Hello,

did anyone ever set up Authentication via lookups to a Joomla (mysql) database?

What I'd like to do is lookup Joomla users (who are in specific/multiple groups) 
in the Joomla database and then fallback to /etc/passwd authentication to let 
system users authenticate.

I'm running :
# 2.2.35 (b1cb664): /usr/local/etc/dovecot/dovecot.conf
# OS: FreeBSD 11.1-RELEASE-p10 amd64

Thanks in advance,

-Graham-