rdo2: bare metal jobs are failing due to TQE configuration mismatch (overcloud_nodes)

[Matt Young]

Bare metal configurations (all) are failing in rdo2 due to a mismatch in how configuration of the ansible variable overcloud_nodes is defined and used. Since BM doesn't gate changes to TQE this slipped thru. We've been iterating on a patch for some time, using resources in rdo phase 2 to validate the change:

- https://review.openstack.org/#/c/551369

This LP is being created to track current work / resolution of the issue in rdo2. The original commit which caused the breakage was

- https://github.com/openstack/tripleo-quickstart-extras/commit/bf6e31219aed819899d03a302ec79bf3be570f6a

which resolves:

- https://bugs.launchpad.net/tripleo/+bug/1741569
- Quickstart RFE: add an interface to tripleo's hostname_map feature for custom hostnames

This is a promotion blocker for rdo2. We're finding this now because we've been running off stable branches in rdo2, which were 2+ months old. Upon rebasing these internal branches (stable/pike, stable/queens, stable/master) to pick up other needed changes, we found this issue. In the bare metal case, the overcloud_nodes defaults to an empty dict, which is causing the issue.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/551369
Committed: https://git.openstack.org/cgit/openstack/tripleo-quickstart-extras/commit/?id=375867e1b743ad5e82926931bb8d4702c97fb25f
Submitter: Zuul
Branch: master

commit 375867e1b743ad5e82926931bb8d4702c97fb25f
Author: Ronelle Landy <email address hidden>
Date: Fri Mar 9 16:00:29 2018 -0500

    Fix overcloud_nodes check failing branch FF

    overcloud_nodes|length > 0 fails if overcloud_nodes
    is set to empty. This review checks for overcloud_nodes[0]
    to be defined.

    Closes-Bug: #1755670
    Change-Id: I5541c913478241042afd366d93aba00247b48a58

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-quickstart-extras 2.1.1 release.