hiera_hash_data_binding

Data binding terminus for Puppet 3+ that changes the way puppet looks class parameters up in hiera. Drop-in replacement for the Hiera data binding terminus.

Instead of querying every class parameter in hiera, hiera is queried for every class to provide a hash where the keys are the class parameters. An small example illustrate the differences:

With the original hiera data binding configuring the parameters of the class ntp looks like this:

ntp::package_ensure: 'latest'
ntp::preferred_servers:
  - ntp1.example.com
  - ntp2.example.com

for every parameter of the class ntp which should be configured an entry is made. With the HieraHash data binding terminus a class entry is made and all parameters which should be configured are added as keys:

ntp:
  package_ensure: 'latest'
  preferred_servers:
    - ntp1.example.com
    - ntp2.example.com

Adventages

• Slightly faster, because only one hiera call per class must be made instead of one per class parameter per class.
• Class parameters are automatically retrieved as hashes from hiera. Therefore hiera merge behaviours deep or deeper are working for class parameters also.

Disadvantages

• Not official supported
• Hiera data must be converted
• Hiera version 1.x doesn't support segmented keys to look up values in hashes and arrays, so a workaround has to be used to access class parameters in hiera

Installation

Install the module like any other module and in the puppet.conf configuration file in the main section add data_binding_terminus = hiera_hash or change it if it already exists.