DevOps: Puppet, Docker, and Kubernetes

Using arrays of resources

Anything that you can do to a resource, you can do to an array of resources. Use this idea to refactor your manifests to make them shorter and clearer.

How to do it…

Here are the steps to refactor using arrays of resources:

1. Identify a class in your manifest where you have several instances of the same kind of resource, for example, packages:

     package { 'sudo' : ensure => installed }
     package { 'unzip' : ensure => installed }
     package { 'locate' : ensure => installed }
     package { 'lsof' : ensure => installed }
     package { 'cron' : ensure => installed }
     package { 'rubygems' : ensure => installed }

2. Group them together and replace them with a single package resource using an array:

    package { [ 'cron', 'locate', 'lsof', 'rubygems', ...