Puppet Module Cheat Sheet

Modules are directories with a predictable structure.
Puppet can automatically load manifests, files, and plugins from modules in its modulepath.
Use puppet --configprint modulepath to see where Puppet expects to find modules on your system.

Example Module: /etc/puppetlabs/puppet/modules/apache

This directory holds the module's Puppet code.

Each .pp file should contain one and only one class or defined type.
Filenames and class/defined type names are related; see the examples below.
Within a module, the special $module_name variable always contains the module's name.

class apache {
  ...
}

Init.pp is special; it should contain a class (or define) with the same name as the module.

define apache::vhost ($port, $docroot) {
  ...
}

Other classes (and defines) should be named modulename::filename (without the .pp extension).

class apache::config::ssl {
  ...
}

Subdirectories add intermediate namespaces.

This directory holds Ruby plugins, which can add features to Puppet and Facter.

A custom type.

A custom function.

A custom fact.

Nodes can download any files in this directory from Puppet's built-in file server.

Use the source attribute to download file contents from the server.
Use puppet:/// URIs to specify which file to fetch.
Files in this directory are served at puppet:///modules/modulename/filename.

To fetch this file:

file {'/etc/apache2/httpd.conf':
  ensure => file,
  source => 'puppet:///modules/apache/httpd.conf',
}

Puppet's file server can navigate any subdirectories:

file {'/etc/apache2/httpd-ssl.conf':
  ensure => file,
  source => 'puppet:///modules/apache/extra/ssl',
}

This directory holds ERB templates.

To use this template:

file {'/etc/apache2/sites-enabled/wordpress.conf':
  ensure  => file,
  content => template('apache/vhost.erb'),
}