Powershell – Why is the Powershell script returing extra output when run by Nagios NRPE

nagiosnrpepowershell

I have a Powershell script that I'm running via nrpe as an external script. The windows server (2008) is running nsclient++ (nscp.exe) v 0.4.1.102.

The return section of my powershell script looks like this

 } else {
                    write-host "ok $queue|queue = $queue"
                    exit 0
 }

And the wrapper script to call the ps1 file looks like this:

ps1 = cmd /c echo C:\\NetAdmin\\%SCRIPT% %ARGS%; exit($lastexitcode) | powershell.exe -command -

If I run this from a windows command prompt the output looks something like:

ok 93|queue = 93

But when I run is using check_nrpe from my nagios server the output changes to:

ok 93|'queue''=0 '93'=0

Nagios is having an issue processing the performance data.

UPDATE:
After filing a bug report, the software author replied that this is desired behavior, but that there are two options for disabling it in the nsclient.ini:

Globally (All scripts)

[/settings/external scripts/scripts/default]
ignore perfdata = true

Single script

[/settings/external scripts/scripts/check_foo]
ignore perfdata = true

Best Answer

You should try to remove extra spaces around = sign :

write-host "ok $queue|queue=$queue"

By now i cannot explain this behaviour on this version of nsclient++. This is not happening on some previous versions like v0.3.8.76 which works like a charm (at least, as expected without surprises).

Seems that nsclient++ extends spaces as a data with a value of 0. It could be a bug or a wanted behaviour.

I am actually searching for some clues on the Internet, and will try to analyse source code.

Related Solutions

NRPE Error – Unable to Read Output: Troubleshooting

You have a rights problem.

Change the command to:

command[check_openmanage]=sudo /usr/lib/nagios/plugins/additional/check_openmanage -s -e -b ctrl_driver=0 bat_charge

(add sudo)

Then, add the nagios-user to the sudoers:

nagios ALL=(ALL) NOPASSWD:/usr/lib/nagios/plugins/additional/check_openmanage

Or you could just chmod the file... That also works.

If you are using CentOS, Red Hat, Scientific or Fedora, make sure to disable Defaults requiretty in the sudoers file.

Powershell – Passing arguments to a Powershell Script using Nagios NRPE

Arguments can be allowed on multiple levels (depending on how you want to slice your "security"). In essence this means you can allow arguments at the NRPE level as well as the external scripts level (and in your case you probably want them in both places)

You can find some background details here: http://docs.nsclient.org/howto/external_scripts.html#arguments

But disregarding the theory to answer your question you need to enable allow arguments in TWO places (see the following):

[/settings/NRPE/server]
allow arguments=true

[/settings/external scripts]
allow arguments=true

[/settings/external scripts/scripts]
foo=scripts\\foo.bat "argument 1" "argument 2"

The one your missing is the latter one:

[/settings/external scripts]
allow arguments=true

So adding that would resolve your issue.

Edit: Add information about the second issue.

The secondary problem with the power shell launch (see comment to this post) was related to powershell oddness which requires a rather intricate command line syntax:

[/settings/external scripts/scripts]
test = cmd /c echo scripts\test.ps1 "$ARG1$"; exit($lastexitcode) | powershell.exe -command -

The problem was the missing - at the end of the command (correct command above).

Best Answer

Related Solutions

NRPE Error – Unable to Read Output: Troubleshooting

Powershell – Passing arguments to a Powershell Script using Nagios NRPE

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