Both os-migrateLive and evacuate server API actions support a force
flag. If force is set to True in the request then nova does not call the
scheduler but instead tries to blindly copy the source host allocation
to the desitnation host. If the source host allocation contains
resources from more than the root RP then such blind copy cannot be done
properly. Therefore this patch detects such situation and rejects
the forced move operation if the server has complex allocations on the
source host.
There is a separate bluperint
remove-force-flag-from-live-migrate-and-evacuate that will remove the
force flag in a new API microversion.
Note that before the force flag was added to these APIs Nova bypassed the
scheduler when the target host was specified.
Blueprint: use-nested-allocation-candidates
Change-Id: I7cbd5d9fb875ebf72995362e0b6693492ce32051
fd351903a1