Open Stack

On 11/13/2015 07:30 PM, Cathy Zhang wrote:
> Has the OVN code been released in Liberty? If not when is it planned for
> release?

No.  OVN itself is still under heavy development within the OVS project.
 It's being developed in OVS master, but is not yet in any released
version of OVS.

You can try it out with Liberty, but there are some catches since it's
sitll so new.  You have to install OVS and OVN from OVS git master.  You
also need kernel support for OVS+conntract integration.  That
integration is in Linux 4.3, but there is also a backport of that
integration that be compiled and loaded into older kernels.  The
networking-ovn devstack plugin does all of this automatically.

The other major catch with using this with Liberty is that it still used
Neutron's L3 agent, which is only temporary.  L3 support is moving fast
in OVN itself, but native NAT support in OVS is still a work in
progress, but we should have something in the coming weeks.

That's a long answer to say that it's available for dev and early
testing now, but I think Mitaka is a more reasonable OpenStack release
to expect a more complete release with all of OVN's native features
integrated into OpenStack.

> Will it replace existing OVS Driver and OVS Agent or it will provide an
> alternative path of programming the OVS?

The future there is not clear.  There's certainly no official plan from
the Neutron project perspective.

OVN is an alternative to the existing OVS integration.  It won't use the
ovs agent, l3 agent, or DHCP agent.  (The L3 and DHCP parts are
partially there, but not complete today, though).

I can say that from the OVN project's perspective, it's certainly our
hope that we implement OVN well enough that Neutron (or other similar
projects) *want* to use it over integrating with OVS directly.  I don't
think it will be much longer before we complete support for what I'd
consider core features for the majority of use cases.  However, the
existing OVS integration does a lot.  I'm not sure when we'll reach full
feature parity, or if that even makes sense.  There may be some features
or deployment models that we don't feel are worth supporting in OVN.
This is just going to be an ongoing conversation that evolves over time.

> It is on the networking-sfc project roadmap to
> support OVN integration with SFC.

Great.  To do that, we have to add SFC to OVN itself.  That's what I've
started looking at.  I did an early prototype and have been talking to
people, including networking-sfc devs :-), to get a better idea of
what's required.  I'm hoping we can have something in OVN during this
development cycle.

> We would like to work with you on adding an OVN driver and Agent to
> integrate with the networking-sfc API.

I don't expect there to be any agent.  All of that will be taken care of
by OVN.

> How would you like to proceed with this integration work?

As I mentioned above, the current work is getting SFC in OVN first.  The
design and implementation discussions for that will take place on the
OVS dev mailing list.  I'll try to post a pointer back to openstack-dev
once there's some kind of design to review there.  I'm not sure on the
timeline right now, as I have my hands in several things at once.

-- 
Russell Bryant