With the Icehouse release we announced that there would be no further
backwards-incompatible changes to HOT without a revision bump. However,
I notice that we've already made an upward-incompatible change in Juno:
https://review.openstack.org/#/c/102718/
So a user will be able to create a valid template for a Juno (or later)
version of Heat with the version
heat_template_version: 2013-05-23
but the same template may break on an Icehouse installation of Heat with
the "stable" HOT parser. IMO this is almost equally as bad as breaking
backwards compatibility, since a user moving between clouds will
generally have no idea whether they are going forward or backward in
version terms.
(Note: AWS don't use the version field this way, because there is only
one AWS and therefore in theory they don't have this problem. This
implies that we might need a more sophisticated versioning system.)
I'd like to propose a policy that we bump the revision of HOT whenever
we make a change from the previous stable version, and that we declare
the new version stable at the end of each release cycle. Maybe we can
post-date it to indicate the policy more clearly. (I'd also like to
propose that the Juno version drops cfn-style function support.)
cheers,
Zane.
_______________________________________________
OpenStack-dev mailing list
OpenStack-dev@lists.openstack.org
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
