---
upgrade:
  - The diskimage-builder stats have been reworked to be more useful.
    The return code and duration is now stored in
    ``nodepool.dib_image-build.<diskimage_name>.status.<rc|duration>``;
    previously this was split for each image format.  This is
    unnecessary and confusing since the results will always be the
    same, since all formats are generated from the same
    diskimage-builder run.  An additional gauge
    ``nodepool.dib_image_build.<diskimage_name>.status.last_build`` is
    added to make it easy to show relative time of builds in
    dashboards.