Open Stack

On Wed, Aug 26, 2015 at 05:28:47PM +0200, Jan Provazník wrote:
> Hi,
> although rdomanager-oscplugin is not yet under TripleO it should be soon, so
> sending this to TripleO audience.
> 
> Satellite registration from user's point of view is now done by passing
> couple of specific parameters when running "openstack overcloud deploy"
> command [1]. rdomanager-oscplugin checks presence of these params and adds
> additional env files which are then passed to heat and it also generates a
> temporary env file containing default_params required for rhe-registration
> template [2].
> 
> This approach is not optimal because it means that:
> a) registration params have to be passed on each call of "openstack
> overcloud deploy"
> b) other CLI commands (pkg update, node deletion) should implement/reuse the
> same logic (support same parameters) to be consistent

I think the problem can be generalized to say that the CLI should never be
creating environment files internally, and ideally it should also not
contain any hard-coded hidden internal defaults or anything coupled to the
template implementation.

Everything should be provided via -e environment files, exactly like they
are for python-heatclient, and if we need some fall-back defaults, they
should be maintained in a defaults.yaml file somewhere, or, just use the
defaults in the actual heat templates.

I also think the use of special CLI switches should be discouraged or even
deprecated, e.g stuffl like --compute-flavor vs just passing
OvercloudComputeFlavor in an environment file.

> This is probably not necessary because registration params should be needed
> only when creating OC stack, no need to pass them later when running any
> update operation.

Note that this all becomes *much* easier with a properly working heat PATCH
update, which oscplugin is already trying to use:

https://github.com/rdo-management/python-rdomanager-oscplugin/blob/master/rdomanager_oscplugin/v1/overcloud_deploy.py#L436

The problem is PATCH updates were only partially implemented in heat for
Kilo, which I've been trying to fix recently:

https://bugs.launchpad.net/python-heatclient/+bug/1224828

The main part needed to avoid needing all the environment files every time
has now landed:

https://review.openstack.org/#/c/154619

We might consider if that's a valid kilo backport, but for upstream TripleO
this is already available :)

There are a couple still outstanding (to allow not passing the template on
update):

https://review.openstack.org/#/c/205754/
https://review.openstack.org/#/c/205755/

> As a short term solution I think it would be better to pass registration
> templates in the same way as other extra files ("-e" param) - although user
> will still have to pass additional parameter when using rhel-registration,
> it will be consistent with the way how e.g. network configuration is used
> and the "-e" mechanism for passing additional env files is already supported
> in other CLI commands. "_create_registration_env" method [2] would be
> updated to generate&add just user's credentials [3] env file - and this
> would be needed only when creating overcloud, no need to pass them when
> updating stack later.

+1, I think making everything consistent via -e parameters makes sense,
which will then become easier since you'll only have to pass those which
change on update after the heat stuff mentioned above is available to all
using the CLI.

Steve