cloud_init_qemu.sh

#!/bin/bash
IMG=ubuntu-20.04-server-cloudimg-amd64.img
USER_DATA=user-data

if [ ! -f "${IMG}" ]; then
  wget "https://cloud-images.ubuntu.com/releases/focal/release/${IMG}"
  qemu-img resize "${IMG}" +10G
fi

if [ ! -f "${USER_DATA}" ]; then
echo "instance-id: $(uuidgen || echo i-abcdefg)" > meta-data
  cat >user-data <<EOF
#cloud-config
users:
  - default
  - name: qwerty
    groups: sudo
    shell: /bin/bash
    sudo: ['ALL=(ALL) NOPASSWD:ALL']
    ssh_import_id: None
    plain_text_passwd: 'change me, seriously'
    lock_passwd: false
EOF
fi

cloud-localds --disk-format qcow2 cloud.img "${USER_DATA}"

qemu-system-x86_64 \
  -drive file="${IMG}" \
  -drive file=cloud.img \
  -device rtl8139,netdev=net0 \
  -m 2G \
  -serial mon:stdio \
  -smp 2 \
  -vga virtio \
;