Fetching users from external source

[mlstfr at ntcomputer.de]

Hello freeradius users,

I am using freeradius2 on OpenWRT (having very little resources to 
operate), which is working fine. Now I'm trying to load users (usernames 
+ passwords) from an external source for authentication in a guest 
network - the external source is another server which will be running a 
web interface and database to configure guest accounts. My approach 
would be to use wget/curl for fetching the users from the server 
(wrapped in a script), which allows the server to format the user list 
in a way freeradius understands it.

How can I configure freeradius to execute the script on startup and use 
its stdout to later authenticate users against it? Of course, if there 
is another (better) approach on how to fetch the users, I would be happy 
to hear about it :)

Also, guest accounts will be modified while freeradius is running. I 
need a way to inform freeradius (using SIGHUP?) to reload the user list 
from the server. Do you have a recommendation on how to achieve this in 
real-time?

Thank you for your help!