cloud-image-utils

sudo apt install -y qemu-kvm cloud-image-utils
wget https://cloud-images.ubuntu.com/releases/16.04/release/ubuntu-16.04-server-cloudimg-amd64-disk1.img

# cat seed
#cloud-config
password: ubuntu
chpasswd: { expire: False }
ssh_pwauth: True
ssh_import_id: ${USER}

cloud-localds seed.img seed
sudo kvm-spice -m 2048 -drive file=ubuntu-16.04-server-cloudimg-amd64-disk1.img,if=virtio,cache=writeback -cdrom seed.img -net nic,model=virtio -net user,hostfwd=tcp::222-:22
# -balloon virtio

# login credentials:
user: ubuntu
pass: ubuntu

ssh ubuntu@localhost:2222