On Sun, Oct 27, 2013 at 11:23:20PM -0400, Lakshminaraya Renganarayana wrote: > A few us at IBM studied Steve Baker's proposal on HOT Software > Configuration. Overall the proposed constructs and syntax are great -- we > really like the clean syntax and concise specification of components. We > would like to propose a few minor extensions that help with better > expression of dependencies among components and resources, and in-turn > enable cross-vm coordination. We have captured our thoughts on this on the > following Wiki page > > https://wiki.openstack.org/wiki/Heat/Blueprints/hot-software-config-ibm-response
Thanks for putting this together. I'll post inline below with cut/paste from the wiki followed by my response/question: > E2: Allow usage of component outputs (similar to resources): > There are fundamental differences between components and resources... So... lately I've been thinking this is not actually true, and that components are really just another type of resource. If we can implement the software-config functionality without inventing a new template abstraction, IMO a lot of the issues described in your wiki page no longer exist. Can anyone provide me with a clear argument for what the "fundamental differences" actually are? My opinion is we could do the following: - Implement software config "components" as ordinary resources, using the existing interfaces (perhaps with some enhancements to dependency declaration) - Give OS::Nova::Server a components property, which simply takes a list of resources which describe the software configuration(s) to be applied This provides a lot of benefits: - Uniformity of interfaces (solves many of the interface-mapping issues you discuss in the wiki) - Can use provider resources and environments functionality unmodified - Conceptually simple, we don't have to confuse everyone with a new abstraction sub-type and related terminology - Resources describing software components will be stateful, as described in (E4), only the states would be the existing resource states, e.g CREATE, IN_PROGRESS == CONFIGURING, and CREATE, COMPLETE == CONFIG_COMPLETE Thoughts? Steve _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
