I have two servers, both running 12.04 server, and nagios-nrpe-server.
On both, I have configured the command check_apt, which runs /usr/lib/nagios/plugins/check_apt.
On both, nagios-nrpe-server is configured to run as the nagios user.
Unfortunately, on one of the servers, I always receive an OK signal with 0 updates when, from a different server, I run /usr/lib/nagios/plugins/check_nrpe -H hostname -c check_apt, despite there being updates.
I followed this through and noticed that on one server, check_apt runs as the nagios user and does indeed return with a warning or critical when required.
The other, problematic server, always says 0 updates required when run as the nagios user, but will always give the correct response when run as root.
On this problematic server, I also note that the MOTD always displays the wrong number of packages. It's as if neither commands are allowed to access the number of updates for a server.
