We have a Nagios setup here and I'm attempting to add in some Windows checks. Most of them have gone OK, using SNMP for basic system stats and NSClient/check_nrpe for service checks and more. Our old monitoring solution that we're attempting to replace used some Powershell scripts to run queries and gather statistics on running applications and more and alert us if there is a problem.

I've been reading various guides out there on how to integrate these with Nagios and I've had no success so far. The most common thing I'm reading is to add a handler line into nsclient.ini and use that with check_nrpe's -c flag. Problem is I get an unknown handler error when attempting that.

Here's a sample of what I've put into nsclient.ini:
check_export = cmd /c echo scripts\<script>.ps1 | powershell.exe -command -

And the check_nrpe command:
./check_nrpe -H <host> -t 60 -n -c check_export

I know this should work since this server is issued commands with check_nt to check other things, and NRPE is enabled and responding. Any ideas?

Perhaps use this script as a basis for your own scripts?

Everything mentioned in that setup is what I've done before.

Note that these scripts work. They are/were used by Zabbix, the implementation we're replacing. The component that is failing is not Powershell, it is NRPE/NSClient++.

Yeah, post the actual command instead of a "sample"