When trying to make changes to refactor livecd-rootfs, it is difficult to
know what side effects a change may have because of the use of globs on
arch/subarch and the lack of an authoritative list of supported arch
combinations.
This assembles a list of all possible values for $ARCH:$SUBARCH by looking at
all existing uses of $SUBARCH in live-build/auto/config and combining with
etc/default-arches from ubuntu-cdimage:
$ grep + etc/default-arches |grep -vE '(trusty|xenial|bionic|focal)[[:space:]]|appliance'
It also includes a special-case *appliance* glob, because there are many
Ubuntu Core appliance builds and there may be more in the future, and we
don't want to have to update livecd-rootfs with a hard-coded list.
Otherwise, this includes all currently used / supported combinations. The
amd64+kassel subarch is referenced in the code, but stopped being built a
while ago because "end of contract"; and there are some older no-longer-used
subarchs for particular raspi variants, which there is work to clean up
separately. So this should be a no-op wrt buildability of any existing
images on mantic - and if not, that's important for us to know!
The pi images contain redundant copies of cmdline.txt and config.txt in
the boot partition mount-point (which get hidden by the *actual* boot
partition). This commit removes those and simplifies the subarch check
(again, +raspi is the only subarch in use at this point on the Raspberry
Pi images)
systemd-resolved got moved out of the systemd package in kinetic and is
required for bootable buildd environement (as opposed to launchpad buildd)
(LP: #2007419)
This package is needed by ubuntu-advantage-tools for cloud images
only. u-a-t ultimately will drop this entirely in their next release.
(cf: https://github.com/canonical/ubuntu-pro-client/issues/2692)
So instead of putting this in the seeds and then having to deal
with the seed changes to Mantic (after its release) and SRU of
ubuntu-meta, I'd rather have changes in livecd-rootfs done. Once
python3-systemd dependency is dropped from u-a-t, we'll drop it
from livecd-rootfs in Mantic+, too.
For minimized images we do not want to install any recommended packages.
We can do this by setting APT::Install-Recommends to false in apt config
or by passing --no-install-recommends to apt-get install.
