DevOps: Puppet, Docker, and Kubernetes

Using inline templates

Templates are a powerful way of using Embedded Ruby (ERB) to help build config files dynamically. You can also use ERB syntax directly without having to use a separate file by calling the inline_template function. ERB allows you to use conditional logic, iterate over arrays, and include variables.

How to do it…

Here's an example of how to use inline_template:

Pass your Ruby code to inline_template within Puppet manifest, as follows:

cron { 'chkrootkit':
  command => '/usr/sbin/chkrootkit >
    /var/log/chkrootkit.log 2>&1',
  hour    => inline_template('<%= @hostname.sum % 24 %>'),
  minute  => '00',
}

How it works…

Anything inside the string passed to inline_template is executed as if it were an ERB template. That is, anything inside the ...