Ok, looked into this a little today, apologies for replying to my own thread:
On Mon, Dec 21, 2015 at 01:35:54PM +0000, Steven Hardy wrote: > Hi all, > > So I've recently had several discussions related to $subject. > > In summary - there's a requirement to enable underclouds to support > deploying/updating previous versions of OpenStack overclouds. > > So, say I upgrade my liberty undercloud to master/mitaka, I'd like to > ensure the following is possible: > > 1. Maintain any existing (liberty) overcloud without being forced to > immediately upgrade to Mitaka (updating the undercloud can pull in features > required to enable this upgrade however). > > 2. Deploy a new overcloud, with the choice between either liberty or mitaka > > This has some implications related to distributing tripleo-heat-templates > (need to allow for packaging to either install both versions of t-h-t, or > always install all versions via one package), and then there are related > requirements related to tripleoclient (and potentially tripleo-common), so > we maintain backwards compatiblity wrt overcloud deployment/update. > > So, some questions: > > - Do we actually want stable branches for tripleoclient (or even > tripleo-common?) if we have to maintain backwards compatibility? > > - Can we add features to tripleoclient now, to make it easier to > pre-configure known locations for specific releases (this should be > configurable via a config file IMO, not hard-coded)? > > - How might we effectively test this in CI? Have a job which deploys e.g > a stable/liberty overcloud with a master undercloud? > > - How hard would it be to wire in image-building for a previous release > (Mitaka/master undercloud building liberty overcloud-full) - would it be > reasonable to assume existing images and say the undercloud only supports > building images for one release version? Turns out this is pretty easy: https://review.openstack.org/#/c/260144/ This shows how to build a liberty overcloud-full (on a master/mitaka undercloud), then deploy a stable/liberty overcloud. I've not heavily tested, but basically it seems to work OK, I had to apply this pending stable/liberty backport: https://review.openstack.org/#/c/258640/ I think the tripleo.sh patch (and steps outlined in the commit message) may serve as a starting point for CI of this, and I do think we need to remove the stable/liberty branch at least for tripleoclient. Steve __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev