The monitoring aspect will be built on an open source project called Nagios, which is a very popular monitoring tool and fits well in Puppet managed environments, as Puppet has built-in resource types for Nagios resources that make configuration easy.

Nagios uses a client-server architecture where the server issues monitoring check commands to the client that runs on the monitored host and the client returns check results back to the server. Nagios Server runs a database where it stores information about Nagios resources, such as clients, what checks to be run on each client, and the status of checks. Nagios Server also provides a web interface for administrators to view the current status of checks and look at the metrics of checks in the form of simple charts. One of the key features of the server is to trigger monitoring alerts when status of checks changes. Alerts can be configured to be delivered by e-mail, SMS, or by making a request to the API.

Nagios Client...