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Reversing ssh plugin results for notification an going RED

Posted: Wed Dec 21, 2011 6:23 pm
by JohnFM3
I want Nagios to report RED an send notifications when sshd is running.

Is there any good documentation or explanation on how to accomplish this?

Currently I am running nagios 3.x which came with OpenSuSE 11.4

Thanks,
John

Re: Reversing ssh plugin results for notification an going R

Posted: Thu Dec 22, 2011 6:56 pm
by jsmurphy
You definitely have a knack for finding niches that I don't think anyone has filled :lol:. I think you might need to write your own script but this one should be easy, though we are once again straying into the territory of things I've never tried:

Essentially create a script to invert states, Nagios expects an exit code to determine the state of a service which looks like this:
OK - 0
WARNING - 1
CRITICAL - 2
UNKNOWN - 3

Create a command in Nagios that looks like this $USER1$\check_tcp -H $HOSTADDRESS$ -p 22 | invert.sh

invert.sh in pseudo code would do:
$state = $arg1
if [$state = "OK"] then
print "SSH port listening"
exit 2
else
print "SSH port is closed"
exit 0
fi

Re: Reversing ssh plugin results for notification an going R

Posted: Wed Dec 28, 2011 11:08 am
by JohnFM3
Ok, so after some research I found a plugin which does what is needed for any check_plugin. This was provided to me as a result of a email sent to the Icinga team (a fork of nagios) who uses the nagios plugin's. When you install the extra plugin pack, a utility called NEGATE which has the ability to reverse the out put of a plugin.

An example for check_ping..
negate /usr/local/nagios/libexec/check_ping -H host
**Run check_ping and invert result. Must use full path to plugin**

Finding this is very gratifying an shows just how flexible Nagios is.

Thanks,
John