Open Stack

Hello,

Usecase: We have to deploy instances that belong in different domains,
to different compute hosts.

Does anyone else have the same usecase? If so, how did you implement
it?

[The rest of the mail is a more detailed explanation on the question:
what have we tried and probable solutions that we though -- but not
yet implemented.]

* Details

In our Openstack Deployment (Mitaka), we have to support 3 different
domains (besides the default). We need a way to separate the compute
hosts in three groups (aggregates), so that VMs that belong to users
of domain A, start in group A, etc. Initially we assume that each
compute host will belong only to one group, but that might change.

We have looked at the nova filter scheduler [1] and on the
Aggregate_Multitenacy_Isolation filter [2], which is doing what we
want but it works on project level (as demonstrated here [3]). Given
that in one of our domains, we'll have at least 200 projects, we'd
prefer to leave this as a last choice.

Modifying the above filter to make the check based on the "domain",
isn't possible. The object that the filter receives, and contains the
information, is the RequestSpec Object [4]. The information contained
in its fields, doesn't include the domain_id attribute.

* Possible solutions that we've thought of:

1. Write our own filter: Modify a filter to contain a call to
   keystone, where it would send the project_id, and get back it's
   domain. But this feels more like a hack than a proper solution. And
   it might require storing the admin credentials to the node that the
   filters are running (controller?), which we'd like to avoid.

2. Make the separation on another level (project/flavor/image):
   Besides the isolation per project, we could also isolate the hosts,
   by providing different images / flavors to the different
   users. There are available filters for that (image_props_filter
   [6]) , (aggregate_instance_extra_specs [7]). But again, due to the
   high number of projects, this would not scale well.

3. Modify the RequestSpec object: Finally, we could include the
   domain_id field on the object, then modify the
   Aggregate_Multitenacy_Isolation filter, to work on that. Of course
   this would be the most elegant solution. However, (besides not
   knowing how to do that), we don't know what kind of implication
   that will have or how to package / deploy it.


Is anyone having the same usecase? How would you go about solving it?

It's interesting, since we though that this would be a common usecase,
but as far as I've searched, I only found one request about this
functionality in a mailing list from 2013 [8], but didn't seem to have
progressed.

Thank you for your time,
George


[1]:https://docs.openstack.org/nova/latest/user/filter-scheduler.html
[2]:https://github.com/openstack/nova/blob/master/nova/scheduler/filters/aggregate_multitenancy_isolation.py
[3]:https://www.brad-x.com/2016/01/01/dedicate-compute-hosts-to-projects/
[4]:http://specs.openstack.org/openstack/nova-specs/specs/mitaka/implemented/request-spec-object-mitaka.html#
[5]:https://github.com/openstack/nova/blob/master/nova/objects/request_spec.py#L46
[6]:https://github.com/openstack/nova/blob/master/nova/scheduler/filters/image_props_filter.py
[7]:https://github.com/openstack/nova/blob/master/nova/scheduler/filters/aggregate_instance_extra_specs.py
[8]:https://lists.launchpad.net/openstack/msg23275.html


-- 
------------------------------------------------------------------
Georgios Kaklamanos
Research Assistant, e-Science Group, GWDG
mailto: georgios.kaklamanos at gwdg.de
Telefon: 0551 201-26803
------------------------------------------------------------------
GWDG - Gesellschaft für wissenschaftliche
Datenverarbeitung mbH Göttingen
Am Faßberg 11, 37077 Göttingen, Germany

WWW: www.gwdg.de    mailto: gwdg at gwdg.de
Phone: +49 (0) 551 201-1510
Fax:   +49 (0) 551 201-2150
------------------------------------------------------------------
Geschäftsführer: Prof. Dr. Ramin Yahyapour
Aufsichtsratsvorsitzender: Prof. Dr. Christian Griesinger
Sitz der Gesellschaft: Göttingen
Registergericht: Göttingen
Handelsregister-Nr. B 598
------------------------------------------------------------------
Zertifiziert nach ISO 9001
------------------------------------------------------------------

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 5396 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://lists.openstack.org/pipermail/openstack-operators/attachments/20170920/d7480622/attachment.bin>