Prior to change I4244f7dd8fe74565180f73684678027067b4506e in Stein,
conductor would pass a legacy dict request spec to compute during
cold migrate / resize and if compute rescheduled it would not pass
the request spec back to conductor, so the _cold_migrate method in
conductor would have to create a new RequestSpec from components
it had available.
As of that change, compute will send the request spec it got back
to conductor and _cold_migrate avoids the RequestSpec.from_components
call.
There are two issues here:
1. Technically if conductor RPC API is pinned to less than 1.13 the
ComputeTaskAPI.migrate_server method will remove the request spec
from the call to conductor. So conductor (server-side) can still
not get a RequestSpec and need to use from_components. As a result
the TODO in the _cold_migrate method needs to be updated since we
require an RPC API major version bump to make request spec required.
2. Just because conductor is passing compute a RequestSpec object, if
compute RPC API versions are pinned to less than 5.1, conductor will
pass a legacy request spec dict to compute and compute will send that
back to conductor, so the _cold_migrate method needs to handle getting
a request spec that is a dict and convert it to an object. A new test
is added for that case.
Change-Id: I188b7aa9cb220f93e69a68f0c3592b28d41ba5b6
Closes-Bug: #1843090
b36c44c449