[openstack-dev] [TripleO][Heat][Kolla][Magnum] The zen of Heat, containers, and the future of TripleO

Ryan Hallisey rhallise at redhat.com
Wed Mar 23 19:58:02 UTC 2016

>>> Hello,
>>> So Ryan, I think you can make use of heat all the way. Architecture of
>>> kolla doesn't require you to use ansible at all (in fact, we separate
>>> ansible code to a different repo). Truth is that ansible-kolla is
>>> developed by most people and considered "the way to deploy kolla" by
>>> most of us, but we make sure that we won't cut out other deployment
>>> engines from our potential.
>>> So bottom line, heat may very well replace ansible code if you can
>>> duplicate logic we have in playbooks in heat templates. That may
>>> require docker resource with pretty complete featureset of docker
>>> itself (named volumes being most important). Bootstrap is usually done
>>> inside container, so that would be possible too.

>> Heat can call Anisble.

>> Why would it not be Heats responsibility for creating the stack, and
>> then Kolla-ansible for setting everything up?

>> Heat is more esoteric than Ansible.  I expcet the amount of people that
>> know and use Ansible to far outweight the number of people that know
>> Heat.  Let's make it easy for them to get involved.  Use each as
>> appropriate, but let the config with Heat clearly map to a config
>> without it for a Kolla based deploy.

I didn't know heat can call Ansible.  Now that I know that let me refine.
I think it would be nice to have heat use kolla-ansible.

With split-stack/composable-roles, the tripleo-heat-templates are going
to undergo major reconstruction.  So then the questions are, do we
construct the templates to 1) use kolla-ansible or 2) rewrite them with
kolla-ansible logic in heat or 3) go with kolla-kubernetes.

1) This solution involves merging the kolla and tripleo communities.
kolla-tripleo maybe?  This path will come to a solution significantly faster
since it will be completely leveraging the work kolla has done.  I think
ansible is a good tool, but I don't know if it's the best for container

2) This solution is right along the lines of dprince's patch series [1],
but with focus on deploying kolla's containers.  This option has a longer
road than 1.  I think it could work and I think it would be a good

> I'd be happy to hear other opinions on that though. Maybe we don't care
> about any of that container cluster management stuff, and if something
> fails we just let everything run degraded until we can pull in a
> replacement? I don't know.

3) Kolla-kubernetes is only a spec at this point, but with kubernetes the
undercloud would use magnum.  This option to me, has the most upside, but
the longest road.  I think the cluster management tools: replication
controllers, health checks, deployments, ect., would be great additions.

My excitement around kolla-ansible stems from the fact that it is significantly
farther along than kolla-kubernetes.  I haven't done a deployment of
kolla-kuberenetes since we dropped it a year ago.  But having done an evaluation
of it recently, I think it's the best option long term.  Until I use it with
kolla + magnum, I won't know for certain.


[1] - https://review.openstack.org/#/c/295588/5

More information about the OpenStack-dev mailing list