Open Stack

Excerpts from Steven Hardy's message of 2013-06-12 06:14:58 -0700:
> On Wed, Jun 12, 2013 at 03:22:00PM +1200, Robert Collins wrote:
> > https://github.com/stackforge/tripleo-heat-templates has the templates
> > for bringing up OpenStack w/TripleO.
> 
> Awesome, very interesting, thanks for sharing! :)
> 
> Can you provide, or direct me to, any description of your usage of the
> Metadata section for instances, e.g stuff like:
> 

I'm working on some docs to put in the repo now that will explain things.

> OpenStack::Role: stateful
> OpenStack::ImageBuilder::Elements: [ heat-api, heat-engine ]
> 
> I know you have some alternate in-instance agents which replace
> heat-cfntools, but I'd really like more detail to fully understand how it
> all fits together.  In particular, I'm intrigued by the stateful role?
> 

Our replacements for a lot of what cfn-init does are os-config-applier
(soon to be renamed os-apply-config) and os-refresh-config. They are
limited in scope intentionally, and rely on cfn-hup to read new Metadata.
They are also designed to have the elements drive most of what they do
as software that is delivered along with the image.

OpenStack::Role was something I added to drive a PoC which I wrote
there in the same repo called, unassumingly, 'merge.py'. It merges any
instances which have the same role into one. This was my answer for how
to co-locate services. It has a lot of drawbacks and I'm not sure if it
is worth pursuing.

The ImageBuilder::Elements part drives another PoC script I have which
builds the image, uploads it to glance, and then deploys the stack. I
am also hoping that these element names can help us validate the rest
of the Metadata section.