[Puppet Users] hiera and fallback to params?

The "right" thing is to put that default somewhere in hiera. What we do is:

cat /etc/puppet/hiera.yaml
---
:hierarchy:
- %{fqdn}
- %{role}
- %{group}
- common
:backends:
- yaml
- puppet
:yaml:
:datadir: /etc/puppet/environments/%{environment}/data
:puppet:
:datasource: data

so there is both a common.yaml file in your data directory for local
fall back, and an ultimate fallback to puppet variables defined in
<class>::data, so we can manage defaults with in the module for
example our local ntp module has them in modules/ntp/data.pp

-Jon