Open Stack

On Fri, 17 Aug 2018, Tom Barron wrote:

> Has there been a discussion on record of how use of placement by cinder would 
> affect "standalone" cinder (or manila) initiatives where there is a desire to 
> be able to run cinder by itself (with no-auth) or just with keystone (where 
> OpenStack style multi-tenancy is desired)?

This has been sort of glancingly addressed elsewhere in the thread,
but I wanted to make it explicit:

* It's possible now to run placement now with faked auth (the
   noauth2 concept) or keystone. Making auth handling more flexible
   would be a matter of choosing a different piece of middleware.

* Partly driven by discussion with Cinder people and also with fast
   forward upgrade people, there's a feature in placement called
   "PlacementDirect". This makes it possible to interact with
   placement in the same process as the thing that is using it,
   rather than over HTTP. So no additional placement server is
   required, if that's how people want it. More info at:

   https://github.com/openstack/nova/blob/master/nova/api/openstack/placement/direct.py
   http://specs.openstack.org/openstack/nova-specs/specs/rocky/approved/reshape-provider-tree.html#direct-interface-to-placement

   However, since placement is lightweight (a simple-ish wsgi app over
   some database tables) it likely easier just to run it like normal,
   maybe in some containers to allow it to scale up and down easily.

If you have a look at https://github.com/cdent/placedock and some of
the links in the README, the flexibility and lightness may become a
bit more clear.

-- 
Chris Dent                       ٩◔̯◔۶           https://anticdent.org/
freenode: cdent                                         tw: @anticdent