Back-end service support¶
Nrelease of horizon supports
N-1releases of back-end OpenStack services (like nova, cinder, neutron and so on). This allows operators to upgrade horizon separately from other OpenStack services.
Horizon should check features in back-end services through APIs as much as possible by using micro-versioning for nova, cinder and so on and API extensions for neutron (and others if any).
Related to the previous item, features available in
N-4releases (which means the recent four releases including the development version) are assumed without checking the availability of features to simplify the implementation.
Removals and deprecations of back-end feature supports basically follows the standard deprecation policy defined by the technical committee, but there are some notes. Deprecations in back-end services are applied to corresponding horizon features automatically and it is allowed to drop some feature from horizon without an explicit deprecation.
Horizon usually syncs with Django’s Roadmap and supports LTS (long term support) versions of Django as of the feature freeze of each OpenStack release. Supports for other maintained Django versions are optional and best-effort.