Installing a group of files with puppet and hiera

Question

I have a puppet config that correctly installs a file. I want it to install several files. The config looks roughly like this (in the part that is relevant here):

$stuff = hiera('stuff')
$site_filename = $stuff['site_file']

file { "/path/to/my/file/called/$site_filename":
  ensure  => present,
  owner   => 'the-owner',
  group   => 'the-group',
  mode    => 644,
  source  => "puppet:///modules/this-module/$site_filename",
  require => [Package['something'],
      User['someone']]
}
file { "/path/to/my/symlink/called/$site_filename":
  ensure  => 'link',
  target  => "/path/to/my/file/called/$site_filename",
  require => Package['something'],
}

Works great, the right file is installed on the right host. But I'd now like to install a variable number of (very similar) files, the number being different on each host.

My hiera files currently look like this:

stuff:
  site_file: "hey-i-am-the-site-file-on-host-awesomeness"

In principle, I want to say something like this:

stuff:
  site_file: ["hey-i-am-the-site-file-on-host-awesomeness",
              "i-am-also-a-site-file-for-awesomeness",
              "do-not-forget-me-too",
              "someday-you-will-want-me-as-well"]

And here I am hitting the limits of my puppet and hiera knowledge. I understand that when I think I should iterate in puppet, I'm probably wrong, but I'm a bit confused how to do this.

Any pointers on how to do it or what to read about to learn?

Answer 1

Puppet 4 and has some iteration functions that would be applicable here, and these are available also in recent Puppet 3 with the future parser enabled. They are not available in Puppet 3 without the future parser, however, so you need a different solution.

The classic way to approach problems such as this is to rely on the fact that a resource declaration in which the title is an array (literal or array-valued variable) declares a separate resource for each element of the array. This is often combined with a defined type as the resource to directly declare. This combination is roughly equivalent to a foreach loop over the array elements, with the defined-type body as its body. Example:

define mymodule::sitefile() {
    file { "/path/to/my/file/called/$title":
      ensure  => present,
      owner   => 'the-owner',
      group   => 'the-group',
      mode    => 644,
      source  => "puppet:///modules/mymodule/$title",
      require => [Package['something'], User['someone']]
    }

    file { "/path/to/my/symlink/called/$title":
      ensure  => 'link',
      target  => "/path/to/my/file/called/$title",
      require => Package['something']
    }
}

# ...

$stuff = hiera('stuff')
mymodule::sitefile { $stuff['site_file']: }