akamaras

Recently I faced problems setting up check_rbl v1.3.0 plugin at my nagios 3.4.1. From the gui the state of the check would turn to UNKNOWN and the Status Information would return “No output returned from plugin”

Running the plugin from the cli would answer back normally

# /usr/lib/nagios/plugins/check_rbl -H xx.xx.xx.xx  --extra-opts='rbl@/etc/nagios-plugins/check_rbl.ini' -t 60
CHECK_RBL OK - xx.xx.xx.xx BLACKLISTED on 0 servers of 38 | servers=0;0;0 time=0s;;

The plugin wouldn’t answer back when it was executed from nagios because it was executed using the nagios embedded Perl interpreter.

You can check if you have nagios embedded Perl interpreter compiled and enabled by looking for “use_embedded_perl_implicitly” option at your main nagios configuration file

# cat /etc/nagios3/nagios.cfg  | grep use_embedded_perl_implicitly
use_embedded_perl_implicitly=1

If you have it enabled, you can dissable it for this plugin only by editing the perl script

vi /usr/lib/nagios/plugins/check_rbl

And adding “# nagios: -epn” within the first 10 lines of the script for Nagios to detect it.

#!/usr/bin/perl

# nagios: -epn

package main;

# check_rbl is a Nagios plugin to check if an SMTP server is black- or
# white- listed
#
# See  the INSTALL file for installation instructions

You can read more about the embedded Perl interpreter here