Management of nova Host Aggregates and Availability Zones with OpenStack CLI

Here is a list of commands to add and manage compute nodes in availability zones with OpenStack CLI.

It is useful for instance in case you want to spawn an instance on a desired compute node.

• Log in on your OpenStack cli, source cloud-admin environment

• List available compute nodes:

  $ nova hypervisor-list
  +----+---------------------+-------+----------+
  | ID | Hypervisor hostname | State | Status   |
  +----+---------------------+-------+----------+
  | 1  | ct1-r2-s11.maas     | up    | enabled  |
  | 4  | ct1-r3-s11.maas     | up    | enabled  |
  | 6  | ct1-r1-s01.maas     | up    | enabled  |
  ...
  | 24 | ct1-r1-s12.maas     | up    | enabled  |
  | 27 | ct1-r2-s09.maas     | up    | disabled |
  | 30 | ct1-r2-s16.maas     | up    | disabled |
  | 33 | ct1-r1-s09.maas     | up    | enabled  |
  +----+---------------------+-------+----------+
  

• We want to create an instance on ct1-r2-s16 which is currently disabled.

  To enable a compute node:

  $ openstack compute service set –enable <compute-node-hostname> nova-compute

  To disable a compute node:

  $ openstack compute service set –disable <compute-node-hostname> nova-compute

  Also, you can enable/disable compute nodes via Openstack dashboard with Admin credentials

• Create an host aggregate:

  $ openstack aggregate create SingleHostAtCT
  

• Associate nova Availability Zone to the aggregate:

  $ openstack aggregate set --zone SingleHostAtCT-AZ SingleHostAtCT
  

• Associate compute node to the aggregate:

  $ openstack aggregate add host SingleHostAtCT ct1-r2-s16
  

• List host aggregates:

  $ openstack aggregate list
  +----+----------------+-------------------+
  | ID | Name           | Availability Zone |
  +----+----------------+-------------------+
  |  4 | SingleHostAtCT | SingleHostAtCT-AZ |
  +----+----------------+-------------------+
  

• Show details of host aggregate:

  $ openstack aggregate show SingleHostAtCT
  +-------------------+----------------------------+
  | Field             | Value                      |
  +-------------------+----------------------------+
  | availability_zone | SingleHostAtCT-AZ          |
  | created_at        | 2018-09-06T10:29:36.000000 |
  | deleted           | False                      |
  | deleted_at        | None                       |
  | hosts             | [u'ct1-r2-s16']            |
  | id                | 4                          |
  | name              | SingleHostAtCT             |
  | properties        |                            |
  | updated_at        | None                       |
  +-------------------+----------------------------+
  

It is now possible to spawn instances selecting the new AZ from the Availability Zone tab on the dashboard.

• Remove host from aggregate:

  $  openstack aggregate remove host SingleHostAtCT ct1-r2-s16
  

• Delete host aggregate:

  $ openstack aggregate delete SingleHostAtCT