I’ve similar need, i.e. to dd some img (e.g. memtest86.img).
I’ve successfully uploaded the image by cheating base_image=ubuntu/focal, during the deployment it failed at curtin hook and status failed deployment in maas portal (see below for err msg). A quick check on the hdd found that it dd the image on the hdd (and bootable from efi shell). I guess I need to pack curtin/cloud-init or whatever into the img to make it work?
Running curtin builtin curthooks
finish: cmd-install/stage-curthooks/builtin/cmd-curthooks: FAIL: curtin command curthooks
Traceback (most recent call last):
File "/curtin/curtin/commands/main.py", line 202, in main
ret = args.func(args)
File "/curtin/curtin/commands/curthooks.py", line 1886, in curthooks
builtin_curthooks(cfg, target, state)
File "/curtin/curtin/commands/curthooks.py", line 1681, in builtin_curthooks
distro_info = distro.get_distroinfo(target=target)
File "/curtin/curtin/distro.py", line 118, in get_distroinfo
variant_name = variant_os_release['ID']
curtin: Installation failed with exception: Unexpected error while running command.
Command: ['curtin', 'curthooks']
Exit code: 3