Expose enable_new_services=True/False as a dedicated config option

[Nobuto Murata]

While enable_new_services=True/False can be specified as "config-flags", but would be nice to be a dedicated config option.

When a deployment rely on host aggregates to distinguish the type of nova-compute hosts (KVM vs LXD or Generic vs SR-IOV), it's not convenient that the new host will be enabled out of the box with the default AZ (nova).

By setting enable_new_services=False, the new node will be added as "disabled" state with the message "New compute service disabled due to config option". The administrator can configure host aggregates, etc. to the node before manually enabling the node.

See the example output below.

$ openstack compute service list --service nova-compute --long
+----+--------------+---------+------------+----------+-------+----------------------------+----------------------------------------------------+
| ID | Binary | Host | Zone | Status | State | Updated At | Disabled Reason |
+----+--------------+---------+------------+----------+-------+----------------------------+----------------------------------------------------+
| 31 | nova-compute | nodz001 | myaz-foo-a | enabled | up | 2018-03-26T01:27:48.000000 | None |
| 34 | nova-compute | nodp004 | myaz-foo-a | enabled | up | 2018-03-26T01:27:39.000000 | None |
| 40 | nova-compute | nodp005 | myaz-foo-b | enabled | up | 2018-03-26T01:27:43.000000 | None |
| 43 | nova-compute | nodp001 | myaz-foo-a | enabled | up | 2018-03-26T01:27:47.000000 | None |
| 46 | nova-compute | nodp002 | myaz-foo-b | enabled | up | 2018-03-26T01:27:41.000000 | None |
| 52 | nova-compute | nodz003 | nova | disabled | up | 2018-03-26T01:27:39.000000 | New compute service disabled due to config option. |
| 55 | nova-compute | nodp006 | nova | disabled | up | 2018-03-26T01:27:40.000000 | New compute service disabled due to config option. |
| 58 | nova-compute | nodz002 | myaz-foo-b | enabled | up | 2018-03-26T01:27:41.000000 | None |
| 61 | nova-compute | nodp003 | nova | disabled | up | 2018-03-26T01:27:39.000000 | New compute service disabled due to config option. |
+----+--------------+---------+------------+----------+-------+----------------------------+----------------------------------------------------+
-----+-------+----------------------------+----------------------------------------------------+

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/637853

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/637853
Committed: https://git.openstack.org/cgit/openstack/charm-nova-cloud-controller/commit/?id=5f21ea7124882f9f3ef4654d6b4421531d229b41
Submitter: Zuul
Branch: master

commit 5f21ea7124882f9f3ef4654d6b4421531d229b41
Author: Andre Ruiz <email address hidden>
Date: Tue Feb 19 11:10:52 2019 -0300

    Implement new option: enable_new_services

    This change implements a new option in config.yaml that allows
    services to come up disabled and be manually enabled later.

    Change-Id: I345b56e347b63650ee3df07773ccb2e333610355
    Closes-Bug: #1758776