Description of problem:

   Neutron agents in HA mode, should share the same host ID (set in [DEFAULT]/host=same-host-id) across all the 3 nodes.

   This is used, so, when a node which has neutron agents fails over to another host, will pick up all the resources (virtual routers, dhcp, lbbas instances) that were assigned to the same host id.

   By default host id is the FQDN of the host (macxxxxxxxxxx.domain.com).

   Without this set, if you failover a host where the agents are running, those will be restarted in another, but won't setup any resource, thus, dhcp, routing, etc will be broken.(those would need to be manually migrated via dhcp-agent-network-remove / dhcp-agent-network-add, l3-agent-router-remove/l3-agent-router-add).

Version-Release number of selected component (if applicable):
foreman-installer-1.6.0-0.2.RC1.el6ost

How reproducible:

always

Steps to Reproduce:
1.install
2.check on the 3 HA controller nodes:  # grep ^host /etc/neutron/*
3.another way to check: ]# neutron agent-list


This shouldn't show individually registered hosts as agents (which will be
populated when we failover all over the hosts). and instead of showing hosts as FQDN's there should be a fixed host "virtual id"

Actual results:
# grep ^host /etc/neutron/* 
in HA controllers is empty

[root@mac000af77993ce ~(openstack_admin)]# neutron agent-list
+--------------------------------------+--------------------+-----------------------------+-------+----------------+
| id                                   | agent_type         | host                        | alive | admin_state_up |
+--------------------------------------+--------------------+-----------------------------+-------+----------------+
| 388d9178-f226-48f4-b81d-a2d96a449571 | DHCP agent         | mac000af77993ce.example.com | xxx   | True           |
| 4c0646c6-f2da-4b12-a53b-48784a7fdd4b | DHCP agent         | mac000af7799318.example.com | :-)   | True           |
| 545f7f25-0413-4e3c-a276-e7be3be2421a | Metadata agent     | mac000af7799318.example.com | :-)   | True           |
| 54b07c0a-d6fc-4ad2-9fa1-f9955b4c8251 | L3 agent           | mac000af77993ce.example.com | xxx   | True           |
| 583d6112-89b9-4e7d-9258-e96d8a3a04db | L3 agent           | mac000af779931a.example.com | xxx   | True           |
| 63a49aea-3ea0-45a7-88ba-ab9397481503 | Metadata agent     | mac000af77993ce.example.com | xxx   | True           |
| 71dc94b6-79cb-473a-bed6-a6afdc84db91 | DHCP agent         | mac000af779931a.example.com | xxx   | True           |
| 72f349a7-a468-4003-8bc3-3e567bf2b84c | Open vSwitch agent | mac000af779932a.example.com | :-)   | True           |
| 7ed67260-ea17-4a24-bacc-e5689a917ac8 | Open vSwitch agent | mac000af7799318.example.com | :-)   | True           |
| 8ddb0aae-5425-45b3-a110-880f3d20e286 | Open vSwitch agent | mac000af77993ce.example.com | xxx   | True           |
| a1289d63-6283-41f9-bf7d-ad4cd533b31a | Open vSwitch agent | mac000af779931a.example.com | xxx   | True           |
| cbe064b1-f3c2-42c9-be3a-cda44385c18a | Metadata agent     | mac000af779931a.example.com | xxx   | True           |
| deaa6571-cc8e-48fc-85bd-44f04def7e14 | L3 agent           | mac000af7799318.example.com | :-)   | True           |
+--------------------------------------+--------------------+-----------------------------+-------+----------------+

Expected results:
# grep ^host /etc/neutron/*
should be set to anything.

[root@mac000af77993ce ~(openstack_admin)]# neutron agent-list
+--------------------------------------+--------------------+-----------------------------+-------+----------------+
| id                                   | agent_type         | host                        | alive | admin_state_up |
+--------------------------------------+--------------------+-----------------------------+-------+----------------+
| 583d6112-89b9-4e7d-9258-e96d8a3a04db | L3 agent           | neutron-n                   | :-)   | True           |
| 71dc94b6-79cb-473a-bed6-a6afdc84db91 | DHCP agent         | neutron-n                   | :-)   | True           |
| 72f349a7-a468-4003-8bc3-3e567bf2b84c | Open vSwitch agent | mac000af779932a.example.com | :-)   | True           |
| a1289d63-6283-41f9-bf7d-ad4cd533b31a | Open vSwitch agent | neutron-n                   | :-)   | True           |
| cbe064b1-f3c2-42c9-be3a-cda44385c18a | Metadata agent     | neutron-n                   | :-)   | True           |
+--------------------------------------+--------------------+-----------------------------+-------+----------------+

Additional info:
We are looking into what was going to be an alternative solution to same-id across all nodes, but, which could be the standard solution from the start.

In that solution we just instruct pacemaker to set the host= parameter dynamically, so we will have 2A + 1P node by default. And the virtual host id will be roamed from the failed host to the new host.

So, in other conditions I would be asking to set the host= parameters via puppet to the config files, but instead, the proposal is to use the new neutron-scale ocf script to fix the issue.