Change Ib984c30543acb3ca9cb95fb53d44d9ded0f5a5c8, which was added
in Newton when cells v2 was optional, added some transitional code
to the API for looking up an instance, which didn't rely on instance
mappings in a cell to find the instance if the minimum nova-osapi_compute
service version was from before Ocata.
People have reported this being a source of confusion when upgrading
from before Ocata, when cells v2 wasn't required, to Ocata+ where cells
v2 along with the mapping setup is required. That's because they might
have older nova-osapi_compute service version records in their 'nova'
(cell) database which makes the API think the code is older than it
actually is, and results in an InstanceNotFound error.
This change does two things:
1. Adds a warning to the compute API code in this scenario to serve
as a breadcrumb if a deployment hits this issue.
2. A nova-status check to look for minimum nova-osapi_compute service
versions across all cells and report the issue as a warning. It's
not an upgrade failure since we don't know how the nova-api service
is configured, but leave that investigation up to the deployer.
This is also written in such a way that we should be able to backport
this through to stable/ocata.
Conflicts:
doc/source/cli/nova-status.rst
NOTE(mriedem): The conflict is because the Rocky section
in the man page does not exist in Queens. The note about
the new check is added to the Queens section and mentions
it was backported from Rocky.
Change-Id: Ie2bc4616439352850cf29a9de7d33a06c8f7c2b8
Closes-Bug: #1759316
(cherry picked from commit eaf6340847)
aaa259d9d3