Hello,

Please find below a patch for guestfs-tools to add Ubuntu 24.04 (noble)
virt-builder template support via the official cloud image.

Ubuntu 24.04 (noble) no longer publishes the legacy debian-installer
netboot tree:

  http://archive.ubuntu.com/ubuntu/dists/noble/main/installer-amd64/ -> 404

make-template.ml depends on that path (preseed + virt-install), so it
cannot build noble templates.

This patch adds make-ubuntu-cloud-template.sh, which downloads the
official noble server cloud image, applies the same customizations as
existing Ubuntu virt-builder templates (root password, cloud-init
disabled, builder user removed), converts to raw, compresses with xz,
and writes a valid index fragment.  detect-cloudimg-expand.sh finds the
expand= partition (cloudimg-rootfs on noble).  make-template.ml now
directs ubuntu 24.04 users to the cloud script.

Tests:
- test-make-ubuntu-cloud-template.sh (argument checks, expand helper,
  cloud URL reachability, noble installer-amd64 absent)
- test-make-template-noble.sh (make-template.ml redirect)
- test-make-ubuntu-cloud-template-integration.sh (slow; downloads image)

Validated manually on Ubuntu noble with libguestfs-tools: virt-ls,
guestmount, virt-index-validate on generated index fragment.

subramanianaug@gmail.com (1):
  builder: add Ubuntu 24.04 cloud-image template builder

 builder/templates/Makefile.am                 |  16 +-
 builder/templates/README-ubuntu-cloud.md      |  52 ++++++
 builder/templates/detect-cloudimg-expand.sh   |  67 +++++++
 builder/templates/make-template.ml            |   5 +
 .../templates/make-ubuntu-cloud-template.sh   | 165 ++++++++++++++++++
 builder/templates/test-make-template-noble.sh |  39 +++++
 ...-make-ubuntu-cloud-template-integration.sh |  52 ++++++
 .../test-make-ubuntu-cloud-template.sh        |  77 ++++++++
 8 files changed, 472 insertions(+), 1 deletion(-)

The patch itself follows in a separate message. I would appreciate any
review and feedback.

Thank you.