nova-compute error after enrolling ironic baremetal nodes

[Tzu-Mainn Chen]

Description
===========
After enrolling some ironic baremetal nodes, I noticed the following in nova-compute.log (longer trace below):

2018-08-30 17:00:51.142 7 ERROR nova.compute.manager [req-73ba9d4b-b51d-4ab7-88c8-5fc3f27fd89e - - - - -] Error updating resources for node 0e5705cc-e872-49aa-aff4-1a91278b5cb3.: NotImplementedError: Cannot load 'id' in the base class

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

* Enroll ironic baremetal nodes (openstack baremetal node provide)
* Wait
* Error repeatedly appears in nova-compute.log

Expected result
===============
No errors in log

Actual result
=============
Errors in log

Environment
===========
openstack-nova-compute-18.0.0-0.20180829095234.45fc232.el7.noarch
puppet-nova-13.3.1-0.20180825165256.5d1889b.el7.noarch
python-nova-18.0.0-0.20180829095234.45fc232.el7.noarch
python-novajoin-1.0.19-0.20180828183900.3d58511.el7.noarch
openstack-nova-common-18.0.0-0.20180829095234.45fc232.el7.noarch
python2-novaclient-11.0.0-0.20180807085257.f1005ce.el7.noarch

Logs & Configs
=============
2018-08-30 17:00:51.142 7 DEBUG oslo_concurrency.lockutils [req-73ba9d4b-b51d-4ab7-88c8-5fc3f27fd89e - - - - -] Lock "compute_resources" release\
d by "nova.compute.resource_tracker._update_available_resource" :: held 0.001s inner /usr/lib/python2.7/site-packages/oslo_concurrency/lockutils\
.py:285
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager [req-73ba9d4b-b51d-4ab7-88c8-5fc3f27fd89e - - - - -] Error updating resources for node 0e57\
05cc-e872-49aa-aff4-1a91278b5cb3.: NotImplementedError: Cannot load 'id' in the base class
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager Traceback (most recent call last):
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 7729, in _update_av\
ailable_resource_for_node
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager rt.update_available_resource(context, nodename)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/nova/compute/resource_tracker.py", line 700, in up\
date_available_resource
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager self._update_available_resource(context, resources)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/oslo_concurrency/lockutils.py", line 274, in inner
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager return f(*args, **kwargs)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/nova/compute/resource_tracker.py", line 723, in _u\
pdate_available_resource
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager self._init_compute_node(context, resources)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/nova/compute/resource_tracker.py", line 563, in _i\
nit_compute_node
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager self._setup_pci_tracker(context, cn, resources)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/nova/compute/resource_tracker.py", line 594, in _s\
etup_pci_tracker
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager n_id = compute_node.id
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 67, in getter
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager self.obj_load_attr(name)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 603, in obj_l\
oad_attr
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager _("Cannot load '%s' in the base class") % attrname)
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager NotImplementedError: Cannot load 'id' in the base class
2018-08-30 17:00:51.142 7 ERROR nova.compute.manager