Include file conditionally based on a bash script

Question

I have a bash command that will return either 1 or 0. I want to run said command from puppet:

exec { 'Check if Thinkpad':
  command     => 'sudo dmidecode | grep -q ThinkPad && echo 1 || echo 0',
  path        => '/usr/bin/:/bin/bash/',
  environment => "HOME=/root"
}

Is there a way I can include a file using puppet only if my command returned 1?

file { '/etc/i3/config':
  source => 'puppet:///modules/i3/thinkpad',
  owner  => 'root',
  group  => 'root',
  mode   => '0644',
}

Answer 1

You can use an external fact to use the bash script as is. Inside the module's facts.d directory, you could place the script.

#!/bin/bash
if [ dmidecode | grep -q ThinkPad ]
  echo 'is_thinkpad=true'
else
  echo 'is_thinkpad=false'
fi

You can also use a custom fact inside the lib/facter directory of your module.

Facter.add(:is_thinkpad) do
  confine kernel: linux
  setcode do 
    `dmidecode | grep -q ThinkPad && echo true || echo false`
  end
end

In both cases, the fact name of is_thinkpad follows the convention for the nomenclature of boolean facts for types of systems. You can then update the code in your manifest for this boolean.

if $facts['is_thinkpad'] == true {
  file { '/etc/i3/config':
    source => 'puppet:///modules/i3/thinkpad',
    owner  => 'root',
    group  => 'root',
    mode   => '0644',
  }
}

This will provide you with the functionality you desire.

https://docs.puppet.com/facter/3.6/custom_facts.html#adding-custom-facts-to-facter https://docs.puppet.com/facter/3.6/custom_facts.html#external-facts