Using modules

One of the most important things you can do to make your Puppet manifests clearer and more maintainable is to organize them into modules.

A module is simply a way of grouping related things: for example, a webserver module might include everything necessary for a machine to be a web server: Apache configuration files, virtual host templates, and the Puppet code necessary to deploy these.

Separating things into modules makes it easier to re-use and share code; it's also the most logical way to organize your manifests. In this example we'll create a module to manage memcached, a memory caching system commonly used with web applications.

How to do it…

Here are the steps to create an example module.

1. Create the following new directories in your Puppet repo:

   ubuntu@cookbook:~/puppet$ mkdir modules/memcached
   ubuntu@cookbook:~/puppet$ mkdir modules/memcached/manifests
   ubuntu@cookbook:~/puppet$ mkdir modules/memcached/files
   

2. Create the file modules/memcached/manifests/init.pp with the following...