Hi all, Recently I've been adding review comments, and having IRC discussions about changes to update behavior for CloudFormation compatible resources.
In several cases, folks have proposed patches which allow non-destructive update of properties which are not allowed on AWS (e.g which would result in destruction of the resource were you to run the same template on CFN). Here's an example: https://review.openstack.org/#/c/98042/ Unfortunately, I've not spotted all of these patches, and some have been merged, e.g: https://review.openstack.org/#/c/80209/ Some folks have been arguing that this minor deviation from the AWS documented behavior is OK. My argument is that is definitely is not, because if anyone who cares about heat->CFN portability develops a template on heat, then runs it on CFN a non-destructive update suddenly becomes destructive, which is a bad surprise IMO. I think folks who want the more flexible update behavior should simply use the native resources instead, and that we should focus on aligning the CFN compatible resources as closely as possible with the actual behavior on CFN. What are peoples thoughts on this? My request, unless others strongly disagree, is: - Contributors, please check the CFN docs before starting a patch modifying update for CFN compatible resources - heat-core, please check the docs and don't approve patches which make heat behavior diverge from that documented for CFN. The AWS docs are pretty clear about update behavior, they can be found here: http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-template-resource-type-ref.html The other problem, if we agree that aligning update behavior is desirable, is what we do regarding deprecation for existing diverged update behavior? Steve _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
