guestfish

Manipulate qcow2 images with the guest filesystem shell

I recently found this handy tool called guestfish. It is great for manipulating disk images in a precise manner without much workflow overhead.

sudo guestfish --rw --add "my-cool-image.qcow2" -i <<EOF
   write /root/.ssh/authorized_keys  "$(cat "~/.ssh/id_ed25519.pub")"
   upload local_file.txt             /etc/foo/bar.txt
EOF