Open Stack

Looking over the things in the runways queue [1], excluding the zVM 
driver (because I'm not sure what the status is on that thread), the 
next in line is blueprint list-show-all-server-migration-types [2].

I know this has been approved since Pike, but I wanted to raise some 
questions again [3] about whether or not we actually need this.

Looking at the spec, the problem description is totally tied to the 
abort in-progress cold migration blueprint [4] which we haven't agreed 
to do. We talked about that blueprint at the PTG in Dublin and the 
action item [5] was for Takashi to follow up in the mailing list (dev 
and operators) to determine if that is functionality people actually 
need. I haven't seen that happen yet.

If we aren't going to add the ability to abort a cold migration, I'm not 
sure why we need list-show-all-server-migration-types. The use case in 
the spec is something an admin can do today with the GET /os-migrations 
API [6]. That should at least be an alternative in the spec.

So beyond being a dependency to abort an in-progress cold migration, 
what would be the other reasons for 
list-show-all-server-migration-types? Because if that is the only thing, 
I think it likely should be held up and dependent on [4] being approved, 
otherwise I feel it's churn for little gain. If there are other reasons 
for this beyond a dependency for abort cold migration, the spec should 
likely be updated to clearly indicate what they are.

[1] https://etherpad.openstack.org/p/nova-runways-rocky
[2] 
https://specs.openstack.org/openstack/nova-specs/specs/rocky/approved/list-show-all-server-migration-types.html
[3] 
http://lists.openstack.org/pipermail/openstack-dev/2017-April/115494.html
[4] https://blueprints.launchpad.net/nova/+spec/abort-cold-migration
[5] https://etherpad.openstack.org/p/nova-ptg-rocky (L362)
[6] https://developer.openstack.org/api-ref/compute/#list-migrations

-- 

Thanks,

Matt