Per the discussion in [1], the ironic nodes added to the node cache in
the ironic virt driver may be missing the required field resource_class,
as this field is not in _NODE_FIELDS. In practice, this is typically
not an issue (possibly never), as the normal code path uses a
detailed list to sync all ironic nodes, which contain all fields
(including resource_class). However, some code paths use a single
node query with the fields limited to _NODE_FIELDS, so could result in a
node in the cache without a resource_class.
This change adds resource_class to _NODE_FIELDS.
[1]
https://review.openstack.org/#/c/532288/9/nova/virt/ironic/driver.py@79
Change-Id: Id84b4a47d05532d341a9b6ca2de7e9e66e1930da
Closes-Bug: #1746209
(cherry picked from commit 5895566a42)
6b11eb794f