---
upgrade:
  - |
    A new check is added to ``nova-status upgrade check`` which will scan
    all cells looking for ``nova-osapi_compute`` service versions which are
    from before Ocata and which may cause issues with how the compute API
    finds instances. This will result in a warning if:

    * No cell mappings are found
    * The minimum ``nova-osapi_compute`` service version is less than 15 in
      any given cell

    See https://bugs.launchpad.net/nova/+bug/1759316 for more details.