Scale down fails in split-stack

[Emilien Macchi]

In Train, we added support to execute Ansible tasks just before node(s) are deleted during a scale-down. e.g. RHSM unregister, Nova Compute service teardown, etc.

The issue is that these Ansible tasks only run on the nodes that are given as Nova UUID argument in "openstack overcloud node delete" command and later converted to Ironic hostnames so Ansible knows how to limit the playbooks to a certain group of hosts which are removed.

The lookup obviously fails in split stack since the nodes aren't in Ironic:
msg='IronicAction.node.get_by_instance_uuid failed: Not Found (HTTP HTTPStatus.NOT_FOUND)'

The problem is a bit more than that, and also affects the new nova-less deployment which also doesn't use Nova UUID anymore.

A first step is to skip Ansible if Split-Stack or Nova-less is used in the deployment.
A second step will be to fix the lookup to return a correct hostname so Ansible can run on these nodes before the actual node removal.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/701255

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/701280

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/701255
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=e366245ecdb0075e044f18d5477e22d17fc78e85
Submitter: Zuul
Branch: master

commit e366245ecdb0075e044f18d5477e22d17fc78e85
Author: Emilien Macchi <email address hidden>
Date: Mon Jan 6 12:00:53 2020 -0500

    workbooks/deployment: ignore uuid to hostname errors with splitstack & nova-less

    The lookup that converts a Nova server UUID into a node hostname from
    Ironic doesn't work if the baremetal is managed in split-stack &
    nova-less.

    For the time being we address these 2 use cases, let's just skip Ansible
    scale down tasks for these deployments.

    A proper lookup will be provided in the future and backported down to
    stable/train.

    Change-Id: I90f7f5a8966a6942e5dcfeb753996df420665be7
    Closes-Bug: #1858459

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/701280
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=a1088e862b228089e2fcc508ed06ac6684fbc52c
Submitter: Zuul
Branch: stable/train

commit a1088e862b228089e2fcc508ed06ac6684fbc52c
Author: Emilien Macchi <email address hidden>
Date: Mon Jan 6 12:00:53 2020 -0500

    workbooks/deployment: ignore uuid to hostname errors with splitstack & nova-less

    The lookup that converts a Nova server UUID into a node hostname from
    Ironic doesn't work if the baremetal is managed in split-stack &
    nova-less.

    For the time being we address these 2 use cases, let's just skip Ansible
    scale down tasks for these deployments.

    A proper lookup will be provided in the future and backported down to
    stable/train.

    Change-Id: I90f7f5a8966a6942e5dcfeb753996df420665be7
    Closes-Bug: #1858459
    (cherry picked from commit e366245ecdb0075e044f18d5477e22d17fc78e85)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-common 12.1.0 release.