Open Stack

On 11/03/2015 10:27 PM, Zane Bitter wrote:
> I think we all agree that using something _like_ Kubernetes would be
> extremely interesting for controller services, where you have a bunch of
> heterogeneous services with scheduling constraints (HA), that may need
> to be scaled out at different rates, &c. &c.
>
> IMHO it's not interesting at all for compute nodes though, where the
> scheduling is not only fixed but well-defined in advance. (It's... one
> compute node per compute node. Duh.)
>
> e.g. I could easily imagine a future containerised TripleO where the
> controller services were deployed with Magnum but the compute nodes were
> configured directly with Heat software deployments.
>
> In such a scenario the fact that you can't use Kubernetes for compute
> nodes diminishes its value not at all. So while I'm guessing net=host is
> still a blocker (for Neutron services on the controller - although
> another message in this thread suggests that K8s now supports it
> anyway), I don't think pid=host needs to be since AFAICT it appears to
> be required only for libvirt.
>
> Something to think about...
>

One of the goals of Kolla (and idea of containerizing OpenStack services 
in general) is to simplify upgrades. Scaling and scheduling are 
obviously important points of Kolla, but they are not the only.

The model of upgrade where images of nova-compute, Neutron agents etc. 
are build once, pushed to registry and then pulled on compute nodes 
looks much better for me than traditional upgrade of packages. It also 
may decrease probability of breaking some common dependency during upgrades.

Regards,
Michal