22.04 – Raspberri pi ubuntu server preinstalled “ubuntu-image” definition

I am chasing down how the “preinstalled” raspberry images are being gerated. What I found so far:
[ubuntu-image][1] is the tool for generating those images, which requires a yaml file with the definition of the image to build. Unfortunately I’ve not been able to find the source for the build, in the [models repo][2] the preinstalled one is missing.

I just want to be able to pre-bake images so it can pre-provisioned to the iscsi servers automatically. It is very interesting that in an opensource world, this particular piece is terrible hidden.

It seems that there are some unit tests that contain files that should be ~close to what preinstall is doing on “internal/statemachine/testdata/image_definitions/test_raspi.yaml” in the ubuntu-image repository.

There are multiple places where this is being asked as [here][3], [here][4], [here][5]:
[1]: github.com/canonical/ubuntu-image
[2]: github.com/snapcore/models
[3]: askubuntu.com/questions/1350211/how-to-build-preinstalled-ubuntu-server-image?newreg=ef296b7d605c48b7b40388ba83dfb342
[4]: askubuntu.com/questions/1301519/where-are-the-scripts-that-build-prebuilt-images-for-raspberry-pi
[5]: askubuntu.com/questions/1350211/how-to-build-preinstalled-ubuntu-server-image