Comment 1 for bug 1759316

The code in [1] was added in Newton, and I think we'd be OK to add a warning if you're not using cells v1 and the osapi_compute minimum version is < 15 in that code as a breadcrumb at least, and we could backport that through to queens, pike and ocata.

For nova-status, we'd likely add a check that queries the minimum nova-osapi_compute service version across all cells (API services should really only be in once cell though) and if < 15 we'd emit a warning. The thing about the nova-status check would be, if you had older nova-osapi_compute services in your nova (cell) database from before upgrading to ocata where cells v2 was required, and then you re-configured the API to point the [database]/connection at the nova_cell0 database and created a new 'current' service version, the cross-cell min version check would give a warning for a cell table entry you don't actually care about. The resolution would just be to delete that entry though I think. Alternatively, we could just not look across cells in nova-status and just rely on [database]/connection being set (or at least look in cell0).