Sometimes you may wish to use variables for calling a specific Puppet resources instead of using if-else conditions. Luckily Puppet allows us to use variables in Puppet resource names like classes, modules etc. …

In my case I had several Puppet classes like aem_curator::install_aem62, aem_curator::install_aem63 and aem_curator::install_aem64. To call the right Puppet class for the installation I used the following If-else conditions:

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if $aem_profile == 'aem62' {

    aem_curator::install_aem62 { "${aem_id}: Install AEM profile ${aem_profile}":
      aem_artifacts_base      => $aem_artifacts_base,
      aem_base                => $aem_base,
    }

  } elsif $aem_profile == 'aem63' {

    aem_curator::install_aem63 { "${aem_id}: Install AEM profile ${aem_profile}":
      aem_artifacts_base      => $aem_artifacts_base,
      aem_base                => $aem_base,
    }

  } elsif $aem_profile == 'aem_64' {

    aem_curator::install_aem64 { "${aem_id}: Install AEM profile ${aem_profile}":
      aem_artifacts_base      => $aem_artifacts_base,
      aem_base                => $aem_base,
    }

As you can see this file can be getting to big to keep track of it very easily.

So instead of maintaining such a complex Puppet manifest I want to reduce it to one Puppet resource call by calling a class using the variable aem_profile in the class name. To do so we can call a Puppet resource within Resource[].

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Resource["aem_curator::install_${aem_profile}"]  { "${aem_id}: Install AEM profile ${aem_profile}":
  aem_artifacts_base      => $aem_artifacts_base,
  aem_base                => $aem_base,
}

As you can see, the class call now depends on the variable ${aem_profile}. This variable defines which Puppet class we want to call.

In my case I reduced a manifest of 280 lines down to 40 lines Example.

Cheers