start a microvm with qemu

microvmstart.sh

#!/bin/bash

sudo apt install qemu

wget https://cloud-images.ubuntu.com/releases/jammy/release/unpacked/ubuntu-22.04-server-cloudimg-amd64-vmlinuz-generic
wget https://cloud-images.ubuntu.com/releases/jammy/release/unpacked/ubuntu-22.04-server-cloudimg-amd64-initrd-generic
wget https://cloud-images.ubuntu.com/releases/jammy/release/ubuntu-22.04-server-cloudimg-amd64-disk-kvm.img

qemu-img create -f qcow2 -F qcow2 -b `pwd`/ubuntu-22.04-server-cloudimg-amd64-disk-kvm.img test.img 8G

cat >user-data <<EOF
#cloud-config

hostname: ubuntu1
fqdn: ubuntu1.localdomain
manage_etc_hosts: true

ssh_pwauth: true
disable_root: true

users:
  - name: ubuntu
    home: /home/ubuntu
    shell: /bin/bash
    groups: sudo
    sudo: ALL=(ALL) NOPASSWD:ALL
    passwd: \$6\$rounds=4096\$DiGfrvgin.sMd183\$FP9xuny2Xv6zgaqCt5sfiWpTOjhzRwfr57H.0J0DZmHJMWjdDScT54XPQvbN3uJBAuTYIuxiLqFsg9zODTIzl1
    # password: test
    lock_passwd: false
    ssh-authorized-keys:
      - `cat ~/.ssh/id_rsa.pub`

EOF

cloud-localds user-data.img user-data

sudo qemu-system-x86_64 \
   -M microvm,x-option-roms=off,pit=off,pic=off,isa-serial=off,rtc=off,accel=hvf\
   -enable-kvm -cpu host -m 2G -smp 2 \
   -kernel ubuntu-22.04-server-cloudimg-amd64-vmlinuz-generic \
   -initrd ubuntu-22.04-server-cloudimg-amd64-initrd-generic \
   -append "earlyprintk=hvc0 console=hvc0 root=/dev/vda1" \
   -nodefaults -no-user-config -nographic \
   -chardev stdio,id=virtiocon0 \
   -device virtio-serial-device \
   -device virtconsole,chardev=virtiocon0 \
   -drive id=test,file=test.img,format=qcow2,if=none \
   -device virtio-blk-device,drive=test \
   -netdev user,id=net0,net=192.168.76.0/24,dhcpstart=192.168.76.9,hostfwd=tcp:0.0.0.0:2222-:22 \
   -device virtio-net-device,netdev=net0 \
   -drive file=user-data.img,format=raw,id=mytest \
   -device virtio-blk-device,drive=mytest \
   -daemonize