This allows us to discover and map compute hosts by service instead of
by compute node, which will solve a major deployment ordering problem for
people using ironic. This also allows closing a really nasty race when
doing HA of nova-compute/ironic.
Conflicts:
doc/source/cli/nova-manage.rst
NOTE(danms): Conflicts in nova-manage.rst due to queens not having recent
changes to the man page.
Change-Id: Ie9f064cb9caf6dcba2414acb24d12b825df45fab
Closes-Bug: #1755602
(cherry picked from commit 005a66d7e0)
(cherry picked from commit dd90b5dbf3)