Comment 1 for bug 1646147

Maybe we can add some validations but Ceph won't get configured unless the user gives instructions to do so.

This is done by deploying using -e /usr/share/openstack-tripleo-heat-templates/environments/puppet-ceph-external.yaml

In addition to that, there are at least three additional parameters the user needs to provide (from a custom environment file) with the external Ceph cluster details:

parameter_defaults:
  # NOTE: These example parameters are required when using CephExternal
  #CephClusterFSID: '4b5c8c0a-ff60-454b-a1b4-9747aa737d19'
  #CephClientKey: 'AQDLOh1VgEp6FRAAFzT7Zw+Y9V6JJExQAsRnRQ=='
  #CephExternalMonHost: '172.16.1.7, 172.16.1.8'

The deployer is expected to create on the external Ceph cluster a client.openstack (by default, but name can be customized) user, with appropriate privileges on the glance/cinder/nova pools, unless rbd is disabled for all these services (see puppet-ceph-external.yaml)

Finally, the deployer is expected to create on the external Ceph cluster a client.manila (again this is the default, can be customized in manila-cephfsnative-config.yaml) with appropriate privileges for Manila.