openstack qcow2 change root password

dnf install libguestfs-tools

virt-customize -a CentOS-7-x86_64-GenericCloud-2111.qcow2 --root-password password:DDYrTXJZTJldOqimb68ZK5KCmRpbdBOe

[ 0.0] Examining the guest ...

[ 6.4] Setting a random seed

[ 6.4] Setting passwords

[ 7.5] Finishing off

 

Now able to login to new guest as root / pw.