$ wget http://cloud-images.ubuntu.com/daily/server/xenial/current/xenial-server-cloudimg-amd64-disk1.img
$ cp xenial-server-cloudimg-amd64-disk1.img xenial-server-cloudimg-amd64-disk1.img.dist
$ cat > user-data <<EOF
#cloud-config
password: passw0rd
chpasswd: { expire: False }
ssh_pwauth: True
EOF
$ echo "instance-id: i-abcdefg" > meta-data
$ cloud-localds -v seed.img user-data meta-data
wrote seed.img with filesystem=iso9660 and diskformat=raw
$ qemu-system-x86_64 -enable-kvm \
-drive file=xenial-server-cloudimg-amd64-disk1.img,if=virtio \
-drive file=seed.img,if=virtio \
-device virtio-net-pci,netdev=net00 \
-netdev type=user,id=net00,hostfwd=tcp::2222-:22 \
-m 512
# window pops up, login as ubuntu:passw0rd