Node discover fails to find kernel image

Description
===========

Attempting to run `openstack overcloud node discover` fails to find bm-deploy-kernel image in glance. An update three months ago to `openstack overcloud image build` removed the upload of those images to glance.

Steps to reproduce
==================

Following instructions here: https://docs.openstack.org/project-deploy-guide/tripleo-docs/latest/deployment/install_undercloud.html

Then, on this page: https://docs.openstack.org/project-deploy-guide/tripleo-docs/latest/provisioning/node_discovery.html#scanning-bmc-range

$ echo "$DIB_YUM_REPO_CONF"
/etc/yum.repos.d/delorean* /etc/yum.repos.d/tripleo-centos-ceph*.repo

$ openstack overcloud image build

$ openstack overcloud image upload

$ openstack overcloud node discover --range 10.64.1.0/24 --credentials "root:$pass"

Expected result
===============

Running `openstack overcloud node discover --range <range> --credentials "user:pass"` should be able to discover nodes and set the deploy image.

Expected: "Successfully registered node UUID ..."

Here is what I got later, after I modified the code at overcloud_node.py:

http://paste.openstack.org/show/779607/

Actual result
=============

"Kernel image bm-deploy-kernel not found in Glance"

http://paste.openstack.org/show/779606/

Additional information
======================

After investigating further, I discovered that the bm-* images were no longer intended to be uploaded to glance. The change happened a couple months ago:

https://github.com/openstack/python-tripleoclient/commit/7ad1b812fc5e2504e130e0997b741ce3b891f4db#diff-84904835afd9ead54ffafbffda5079f6

At that time, there were some changes made to overcloud_node.py, but only for classes ImportNode and ConfigureNode, and none for DicscoverNode. Inside of DiscoverNode, I found that the default for deploy_kernel and deploy_ramdisk were still using the bm-* images.

I was able to get a successful status from the code by altering the defaults:

http://paste.openstack.org/show/779526/

Which gave the expected result, mentioned above:

http://paste.openstack.org/show/779607/

Also, it seems that this issue may be related to the issue at https://bugs.launchpad.net/tripleo/+bug/1749656, though I haven't been able to replicate that yet.

There are also a few mentions of the bm-* images in the tests as well.

Environment
===========
Stein

Undercloud os: CentOS Linux release 7.6.1810 (Core)

Installed Packages
Name : python2-tripleoclient
Arch : noarch
Version : 12.1.1
Release : 0.20190916222855.c28df72.el7
Size : 2.4 M
Repo : installed
From repo : delorean
Summary : OpenstackClient plugin for tripleoclient
URL : https://pypi.python.org/pypi/python-tripleoclient
License : ASL 2.0
Description :
            : python-tripleoclient is a Python plugin to OpenstackClient
            : for TripleO <https://github.com/openstack/python-tripleoclient>.

Logs & Configs
==============

http://paste.openstack.org/show/779704/