Comment 4 for bug 1512017

This is caused by hiera task being re-run after openstack-network/agents/metadata.pp and before heat.pp tasks. hiera task rewrites /etc/hiera.yaml and removes any plugin configuration. Here's the task list:
 http://paste.openstack.org/show/Fc1eCobjHIufCtcbhpDF/

It should be only run once at the very beginning