Since version 4.0 LXD also natively supports virtual machines and thanks to a built-in agent, they can be used almost like containers.

lxc image list images: | grep VIRTUAL-MACHINE

lxc launch images:ubuntu/21.04 vm2104 --vm
lxc launch images:ubuntu/21.04/cloud vm2104c --vm

Links
https://linuxcontainers.org/lxd/getting-started-cli/#launch-a-virtual-machine

OpenStack admin

openstack image set --property hw_qemu_guest_agent=yes ${IMAGE_ID}

Within the VM

# check whather hw_qemu_guest_agent is enabled
ls -l /dev/virtio-ports/org.qemu.guest_agent.0

# install qemu-guest-agent
sudo apt-get install -y qemu-guest-agent

supported_commands

docker exec -ti nova_libvirt virsh qemu-agent-command instance-000069d9 '{"execute":"guest-info"}'

Execute command

openstack server show d82ca1de-1fcd-4ca6-84db-84891ec37796 -c OS-EXT-SRV-ATTR:hypervisor_hostname -c OS-EXT-SRV-ATTR:instance_name
docker exec -ti nova_libvirt virsh qemu-agent-command instance-000069d9 '{"execute":"guest-network-get-interfaces"}'

Links
https://www.sebastien-han.fr/blog/2015/02/09/openstack-perform-consistent-snapshots-with-qemu-guest-agent/
https://www.ovh.com/blog/create-and-use-openstack-snapshots/
http://wiki.stoney-cloud.org/wiki/Qemu_Guest_Agent_Integration