naga

A python plugin for the Nagios monitoring system that connects to remote hosts via ssh.

The key requirements of naga are:

• NO dependencies on the remote host (only use system commands/files).
• Few dependencies on the local host i.e. nagios server. (only python 2.6+)
• Conform to Nagios plugin gudelines.

Naga can collect the following kinds of information:

• load
• memory (used/free space)
• cpu
• disk (io)
• filesystem (used/free space)
• network (io)

Obviously since naga connects to remote machines via ssh it will not be suitable for monitoring large numbers of machines. The intended use cases for naga are for when you can't or don't want to install any special software on the remote machine.

Installation

To install copy naga.py to /usr/lib/nagios/plugins/ or wherever you have your nagios plugins installed. You then need to define a command in your nagios config. One example follows:

define command {
    command_name naga_check_host
    command_line /usr/lib/nagios/plugins/naga -H $HOSTNAME$ -i $SERVICEDESC$ 
    }

Then you can define a service like so:

define service {
    hostgroup_name          ssh-servers
    service_description     load
    check_sommand           naga_check_host
    use                     generic-service
    }

Supported environments

As of 14 Aug 2013 Naga has been tested with the following remote hosts:

• Ubuntu 10.04, 12.04, 13.04 (ok)
• RedHat 5/6 (ok)
• RHEL ES release 3 (no network)

And the following non-linux operating systems:

• HP-UX (disk, filesytem only)
• XServe (filesystem only).

Most of the non-working cases are due to missing files. Eg. /proc/stat

Your mileage may vary on other operating systems. The goal was to use system commands and files that will always be available, so please log bugs/issues if that is not the case on Linux. Or if there is a lower-common-denominator command/file that can be used.

Testing

A small python test suite (using unittest/nose) is provided. To run the tests install nose, then cd to project directory and run:

nosetests

If the ssh command returns some output that naga cannot process then you can add the argument --capture=test/static/filename.txt to capture the output for further debugging. If you're really adventurous you can write a regression test in test/testnaga.py using the captured output.