At Wanelo we are committed to sharing as much of our code as possible with the world, since we are ourselves highly reliant on open source movement (ruby, rails, etc). Here is a small but growing project with simple BASH shell scripts used by Nagios monitoring system to ensure things are running smoothly. https://github.com/wanelo/nagios-checks Please see the examples in the README on how to use it with nagios.
Tech ramblings by Konstantin Gredeskoul