Creation action: list-compute-nodes

[Alvaro Uria]

In order to script a verification of safe removal of nova-compute units, a new action would be required.

* Action name: list-hypervisors
Return the list of "nova-compute" services registered in Nova.

This information will help filter by available (enabled) hypervisors and match them to the specific list of hosts that we want to remove. The goal is to notify the user that the Nova cluster will be left without hypervisors and no instances could be allocated to run.

[Martin Kalcok (martin-kalcok)]

After some discussion with @aluria we came to the conclusion that this action is better suited for nova-compute charm.

This action is mainly for the purpose of implementing check whether nova-compute unit is safe to reboot/shutdown https://bugs.launchpad.net/juju-verify/+bug/1913700 . As such, it makes more sense to fetch hypervisor list from the unit we are already targeting rather than figuring out which unit is nova-cloud-controller related to the targeted unit.

[Martin Kalcok (martin-kalcok)]

Issue moved to nova-compute repository https://bugs.launchpad.net/charm-nova-compute/+bug/1914060

[Alvaro Uria (aluria)]

Since this action will be implemented in charm-nova-compute, and a new bug has been created for it (see comment #2), I think this bug should be marked as "Invalid" or "Won't fix".

[Alex Kavanagh (ajkavanagh)]

I'm going to add nova-compute as a project to this bug and mark the other one as a duplicate of this one. This is so that the history of the bug (including the decision to move it to nova-compute) can be kept. I'll mark the nova-cloud-controller part of this bug as invalid.

[Martin Kalcok (martin-kalcok)]

We changed slightly design of this action during implementation. It's now called `list-compute-nodes` and returns equivalent to the `openstack compute service list` formatted as a list of dictionaries where each dict describes one registered service. The action output also contains key `host-identity` that allows user to identify which service in the list belongs to the targeted unit.

PR: https://review.opendev.org/c/openstack/charm-nova-compute/+/783383

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/charm-guide/+/788302

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-guide/+/788302
Committed: https://opendev.org/openstack/charm-guide/commit/6aab781214ec6e7fc4254f05eba70eb369b17075
Submitter: "Zuul (22348)"
Branch: master

commit 6aab781214ec6e7fc4254f05eba70eb369b17075
Author: Aurelien Lourot <email address hidden>
Date: Tue Apr 27 15:41:56 2021 +0200

    Add nova-compute 'list-compute-nodes' action to release notes

    Change-Id: If47d33eff64598d134ae10edb15e6693306d0399
    Closes-Bug: #1911013