How to escape the $ in NRPE service

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Overview

This page reviews how to work with escaping the $ in NRPE service arguments. If you are using WMI Proxy to check for a Microsoft Service running on a Host you can employ the check for the service that passes in the service name and possibly the user/password credentials. But if the service name on the Microsoft host has an embedded $ character this will not work unless you properly escape the $.

Steps

Example Scenario

In checking for MSSQLSERVER, Microsoft just said no such name. A quick run of PSTools psservice command revealed the services were running under a different set of names. These names had the form of MSSQL$EFGH. Putting this into the standard check with the Monarch configuration tool resulted in a status of Unknown - MSSQL: not installed. The key information is to use a \$$ to create something that Nagios (and NRPE_NT) will interpret as a single $ in the middle of some other text. If you don't do this, Nagios will interpret the $ and the trailing characters (and later $ characters) as some kind of outer space macro. You may be confused because the configuration Test feature will produce a working result without this sequence, yet paradoxically Nagios does not like the generated config files.

• WMI Proxy IP address (first we'll just pass it as an argument):

  10.10.10.1

• Microsoft service name:

  MSSQL$CVP1SQL

• A basic Monarch configuration check command assumes the WMI Proxy account has rights to do the check.

• Check command name:

  check_wmi_service

• Command line:

  $USER1$/check_nrpe -H $ARG1$ -t 60 -c get_service -a "$HOSTADDRESS$" $ARG2$

• Monarch service name command line:

  check_wmi_service_auth!10.10.10.1!MSSQL\$$CVP1SQL

• Looking at the generated service.cfg and you see:

  check_command check_wmi_service_auth!10.21.130.80!MSSQL\$$CVP1SQL