Kayobe has fairly coarse-grained default groups - controller, compute,
etc, which work well in the majority of cases. Kolla Ansible allows much
more fine-grained placement on a per-service basis, e.g.
ironic-conductor. If the operator has taken advantage of this
fine-grained placement, then it is possible that some of the assumptions
in Kayobe may be incorrect. This is one downside of the split between
Kayobe and Kolla Ansible.
For example, Ironic conductor services may have been moved to a subset
of the top level 'controllers' group. In this case, we would not want
the Ironic networks to be mapped to all hosts in the controllers group -
only those running Ironic conductor services. The same argument can be
made if the loadbalancer services (HAProxy & keepalived) or Neutron
dataplane services (e.g. L3 & DHCP agents) have been separated from the
top level 'network' group.
This change abstracts the placement of Ironic conductor Ironic
inspector, loadbalancer and network services into separate variables,
rather than referencing the top level 'controllers' and 'network' groups
directly. These variables may be updated by the operator to match the
service placement.
Change-Id: Idbf181c795ee98ad653f11ae483f9dab4ef1b599
2071dc9a38