This chapter has been entirely dedicated to how we can extend Puppet functionalities using Ruby code. We have reviewed the different areas where Puppet can be customized, from the indirector and its termini to the plugins we can deliver via modules.

We have reviewed the most common plugins, facts, functions, types and providers, reports, and faces, trying to outline the needed code components without indulging much in specific implementation details.

The best place to look for samples is the Puppet code itself; under the lib/puppet directory, we can find the actual implementation of the core components.

How often we find ourselves working on custom plugins written in Ruby will depend on our needs and skills; we might never need to write any of them, but it is useful to know what they are and the principles behind them.

The scope of this chapter was to provide an overall view in order to be able to find where plugins are placed in a module, know how they integrate into Puppet, and have...