Base os install ad a template in your hypervisor. Ansible playbook with a task to spin up the VM, another task to setup network and required packages. Then other playbooks for the software/services setup.

At work, we use Racetrack, if that counts. It works quite well.

I use Ansible for all my deployments and just got a PXE boot set up with a preseed file to automate the install process and get the host ready to run playbooks.

I've been really pleased with this strategy overall. I think that Ansible works really well for programmatically generating config files which in turn makes moving applications between servers effortless. I control docker volume mounts with ansible variables and encrypt secrets with ansible vault so I can do everything all in one place.

Troubleshooting issues is a lot easier and recovering from a backup is faster and a requires less effort since I can just pull down the Ansible config from git and redeploy.

I use NixOS but I don't bother with automatic deployment or even automatic formatting. I don't feel it's necessary in a homelab setting as hardware failure rarely happens at such small scale and the manual steps left aren't that significant.

Setup a good kickstart script (even if it's just enough for Ansible to Configure it the rest of the way). It's awesome when messing with a system to be able to reboot select the reinstall PXE boot option and get a fresh install to tinker on.