ref_example-template-snippets.adoc

Example template snippets

Example template snippets show the correct ERB template syntax and common use cases. You can use these snippets as a starting point when writing your own templates.

Example 1. Checking if a host has Puppet and Puppetlabs enabled

The following example checks if the host has the Puppet and Puppetlabs repositories enabled:

<%
pm_set = @host.puppetmaster.empty? ? false : true
puppet_enabled = pm_set || host_param_true?('force-puppet')
puppetlabs_enabled = host_param_true?('enable-puppetlabs-repo')
%>

Example 2. Capturing major and minor versions of a host’s operating system

The following example shows how to capture the minor and major version of the host’s operating system, which can be used for package related decisions:

<%
os_major = @host.operatingsystem.major.to_i
os_minor = @host.operatingsystem.minor.to_i
%>

<% if ((os_minor < 2) && (os_major < 14)) -%>
...
<% end -%>

Example 3. Importing snippets to a template

The following example imports the subscription_manager_registration snippet to the template and indents it by four spaces:

<%= indent 4 do
snippet 'subscription_manager_registration'
end %>

Example 4. Conditionally importing a Kickstart snippet

The following example imports the kickstart_networking_setup snippet if the host’s subnet has the DHCP boot mode enabled:

<% subnet = @host.subnet %>
<% if subnet.respond_to?(:dhcp_boot_mode?) -%>
<%= snippet 'kickstart_networking_setup' %>
<% end -%>

Example 5. Parsing values from host custom facts

You can use the host.facts variable to parse values from a host’s facts and custom facts. In this example luks_stat is a custom fact that you can parse in the same manner as dmi::system::serial_number, which is a host fact:

'Serial': host.facts['dmi::system::serial_number'],
'Encrypted': host.facts['luks_stat'],

In this example, you can customize the Applicable Errata report template to parse for custom information about the kernel version of each host:

<%-     report_row(
          'Host': host.name,
          'Operating System': host.operatingsystem,
          'Kernel': host.facts['uname::release'],
          'Environment': host.single_lifecycle_environment ? host.single_lifecycle_environment.name : nil,
          'Erratum': erratum.errata_id,
          'Type': erratum.errata_type,
          'Published': erratum.issued,
          'Applicable since': erratum.created_at,
          'Severity': erratum.severity,
          'Packages': erratum.package_names,
          'CVEs': erratum.cves,
          'Reboot suggested': erratum.reboot_suggested,
        ) -%>