10.2.

$ mkdir cloudinitiso
$ cd cloudinitiso

instance-id: citest
local-hostname: vmname

#cloud-config
user: admin
password: password
chpasswd: {expire: False}
ssh_pwauth: True
ssh_authorized_keys:
  - ssh-rsa AAA...fhHQ== your.email@example.com

# genisoimage -output cloud-init.iso -volid cidata -joliet -rock user-data meta-data

I: -input-charset not specified, using utf-8 (detected in locale settings)
Total translation table size: 0
Total rockridge attributes bytes: 331
Total directory bytes: 0
Path table size(bytes): 10
Max brk space used 0
183 extents written (0 MB)

# virt-install \
    --memory 4096 \
    --vcpus 4 \
    --name myvm \
    --disk rhel-8-x86_64-kvm.qcow2,device=disk,bus=virtio,format=qcow2 \
    --disk cloud-init.iso,device=cdrom \
    --os-variant rhel 8 \
    --virt-type kvm \
    --graphics none \
    --import

Starting install...
Connected to domain mytestcivm
...
[  OK  ] Started Execute cloud user/final scripts.
[  OK  ] Reached target Cloud-init target.

Red Hat Enterprise Linux 8 (Ootpa)
Kernel 4.18.0-221.el8.x86_64 on an x86_64