Open Stack

Thanks for starting the discussion Fabio.

> As someone that started looking into this topic just recently, I'd love to see
> our communities collaborate more wherever possible. For example, it'd be great
> to see us working on a reference architecture for deploying OpenStack on
> kubernetes, letting the implementation details aside for a bit. I'd assume some
> folks have done this already and I bet we can all learn more from it if we work
> on this together.

Agreed Flavio. Members of the kolla-kubernetes community have some ideas of
how this will look.  I can put together some diagrams over the weekend to depict
this and maybe others that have some ideas can comment and share theirs.

> So, let me go ahead and ask some further questions here, I might be missing some
> history and/or context:
> - Is there any public documentation that acts as a reference architecture for
>  deploying OpenStack on kubernetes?

These specs [1][2] might be a good start.

> - Is this something the architecture working group could help with? Or would it
>  be better to hijack one of kolla meetings?

kolla-kubernetes has a booked slot in the weekly kolla meetings. This could be
discussed there.

>> So issue is, I know of few other openstacks on k8s and everyone does
>> that slightly differently. So far we lack proof points and real world
>> data to determine best approaches to stuff. This is still not-to-well
>> researched field. Right now it's mostly opinions and assumptions.
>> We're not ready to make document without having a flame war around
>> it;) Not enough knowledge in our collective brains.

> Awesome input, thanks.

Michal is right, there are a bunch of implementations that exist. The tricky
part is pulling together all the groups to figure out the best solution.

When the kolla-kubernetes project was created, my hope that this new repo would
be a place where anyone curious about the OpenStack and Kubernetes interaction
could come and express their opinion in code or conversation. The community still
remains open to any changes with it's implementation and the current
implementation is a reflection of who is participating.

I agree that it would be ideal for a single place to collaborate. It would be
awesome to bring together the community that is looking to solve this
problem around a single project. Doesn't matter what that project is, but I'd
like for more collaboration :).

>> As for Kolla-k8s we are still deep in development, so we are free to
>> take best course of action we know of. We don't have any technical
>> debt now. Current state of stuff represents what we thing is best
>> approach.

> I wonder if we can start writing these assumptions down and update them as we
> go. I don't expect you to do it, I'm happy to help with this. We could put it in
> kolla-k8s docs if that makes sense to other kolla-k8s folks.

It's not that Kolla-k8s has tech debt, but rather the community is still testing the
waters with its implementation. For instance, the community is looking at a workflow
that will execute the deployment of OpenStack and hand off to Kubernetes to manage it.
This solution raises some questions: why do you need a workflow at all? Why not
use Kubernetes, a Container Orchestration Engine, to orchestrate the services?  A lot
of these fundamental questions were outlined in this spec [1] and the answers to them
are still WIP [3].

> I'll probably start pinging you guys on IRC with questions so I can help writing
> this down.

That would be fantastic! There's also room for collaboration at summit too.
Kolla-kubernetes will have a design session/fishbowl scheduled.

>> There is also part that k8s is constantly growing and it lacks certain
>> features that created these issues in the first place, if k8s solves
>> them on their side, that will affect decision on our side.

> Thanks a lot, Michal. This is indeed the kind of info I was looking for and
> where I'd love to start from.

Agreed Michal.  The community has been adapting on the fly based on features coming
out of Kubernetes.  Things like init containers and petsets were recent features
that have found their way into kolla-kubernetes.

The flow of work in kolla-kubernetes has been following the work items in the
spec [1], but in a different order.  The basic outline for putting OpenStack on
Kubernetes will follow a similar path. Where as things like the templates will
be similar, but the orchestration method can vary. I think that's where the
biggest controversy lies.

Thanks!
-Ryan

[1] - https://review.openstack.org/#/c/304182/
[2] - https://specs.openstack.org/openstack/fuel-specs/specs/10.0/ccp.html
[3] - https://review.openstack.org/#/c/335279/