Integrating Nagios plugin with OpenNMS

OpenNMS is highly scalable enterprise level management system. I like its features of versatile built-in monitors, auto-discovery and graphing ability. It can also work with ngaios plugin to use any customized monitor.

Install OpenNMS

http://www.opennms.org/documentation/InstallStable.html

Setup NRPE on client

yum install nrpe nagios-plugins-nrpe nagios-plugins

#==create a test script
$vi /usr/lib/nagios/plugins/check_test.sh

#!/bin/sh
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
echo "check test"
exit $STATE_OK


$ make sure nagios user has rx permission for the script.
chmod +rx check_test.sh


#vi /etc/nagios/nrpe.cfg
allowed_hosts=127.0.0.1,IP of OpenNMS
command[check_test]=/usr/lib/nagios/plugins/check_test.sh

#==start nrpe
service nrpe start

#==Now test it mannually, It is important to run the check as user nagios not root

sudo -u nagios /usr/lib/nagios/plugins/check_nrpe -n -H localhost -c check_test
sudo -u nagios /usr/lib/nagios/plugins/check_nrpe -H localhost -c check_test
-n = Do no use SSL,if nrpe doesn't support both mode, it is important to set usessl value in opennms config file.

Setup NRPE on OpenNMS system:

yum install nagios-plugins-nrpe nagios-plugins
#==no configuration needed here, first run a mannual test
sudo -u nagios /usr/lib/nagios/plugins/check_nrpe -n -H remote-host -c check_test
sudo -u nagios /usr/lib/nagios/plugins/check_nrpe -H remote-host -c check_test
-n = Do no use SSL. if nrpe doesn't support both mode, it is important to set usessl value in opennms config file.


OpenNMS configuration

Two configuartion files need to be modified for new added service.
/opt/opennms/etc/capsd-configuration.xml /* service definition for initial scan */
/opt/opennms/etc/ poller-configuration.xml /* service definition for constant polling */


/opt/opennms/etc/capsd-configuration.xml
protocol-plugin
protocol-plugin protocol="NRPE-test" class-name="org.opennms.netmgt.capsd.plugins.NrpePlugin" scan="on"
property key="banner" value="*"
property key="port" value="5666"
property key="timeout" value="3000"
property key="retry" value="2"
property key="usessl" value="true"
property key="command" value="check_test"
protocol-plugin

- Important Notes:
Set usessl value depending on your nrpe ssl supporting ability
command used for polling, it better to be set to your customized script(or system built-in cmd: _NRPE_CHECK)

/opt/opennms/etc/ poller-configuration.xml

service name="NRPE-test" interval="300000" user-defined="true" status="on"
parameter key="retry" value="3"
parameter key="timeout" value="3000"
parameter key="port" value="5666"
parameter key="command" value="check_test"
parameter key="usessl" value="true"
parameter key="padding" value="2"
parameter key="rrd-repository" value="/opt/opennms/share/rrd/response"
parameter key="ds-name" value="nrpe-test"
service

- Important Notes:

The name attribute of the service in poller-configuration.xml needs to match the protocol attribute of the protocol-plugin in capsd-configuration.xml.
The ds-name attribute also needs to be unique for each service, or you'll find response time from one service overwriting response time from another.
You'll also need a line to map the new service to a monitor class (see at the end of the file)

monitor service="NRPE-test" class-name="org.opennms.netmgt.poller.monitors.NrpeMonitor"
Restart OpenNMS for the changes to take effect
The new service should be discovered by re-scan.

Troubleshooting
if the new added service can't be discovered, turn on debug on for discovery process capsd

/opt/opennms/etc/log4j.properties

# Capsd
log4j.category.OpenNMS.Capsd=DEBUG, CAPSD
log4j.appender.CAPSD.File=/opt/opennms/logs/daemon/capsd.log


if the new added service can be discovered, but having issue with polling,turn on debug on for polling process poller
/opt/opennms/etc/log4j.properties

# Pollers
log4j.category.OpenNMS.Poller=DEBUG, POLLERS