Add singleton class for problem services
Add singleton class for problem services

The ceilometer-central-agent service can only have
a single copy per cluster. This patch adds a class
that will make sure only the cluster master runs this
service if there are multiple control nodes.

This is not HA at all.

michaeltchapman/puppet-openstacklib,michaeltchapman/puppet-stacktira,michaeltchapman/puppet-stacktira,michaeltchapman/puppet-openstacklib