for rke2 on openstack I can recommand https://github.com/remche/terraform-openstack-rke2 (main author of module here) 😉

I'm not sure, it is that the case. Ate least I don's see any entry point for userdata. Would you give me a hint, where to find it? Cheers

In fact you wont need to provide userdata as it's generated by the module : https://github.com/remche/terraform-openstack-rke2/blob/master/modules/node/files/cloud-init.yml.tpl