I've proposed a change to make a more feature complete rocky element here: https://review.opendev.org/c/openstack/diskimage-builder/+/855521. I was trying to make an image that is compatible with the officially distributed generic cloud images. It is essentially just layering on some additional packages on top of the rocky-container element. Would love to have some more feedback.

On Tue, 2 Aug 2022 at 13:08, Jeremy Stanley <fungi@yuggoth.org> wrote:
On 2022-08-02 12:17:58 +1000 (+1000), Ian Wienand wrote:
[...]
> In terms of having your dependencies available in final images,
> nothing really beats specifying them explicitly.  Something like [1].
> I think I'd encourage this rather than trying to add another platform
> to support in dib.
[...]

And, just to be clear, in OpenDev our goal is to have only the
things necessary to start the VM and connect with Ansible. We do
also cache some expensive-to-retrieve things like Git repositories
and files nearly every job is otherwise going to try to fetch over
the network into these images, in order to improve job startup times
and stability, but job-specific or project-specific dependencies
should be explicitly installed by the jobs themselves.
--
Jeremy Stanley