pct exec $CTID -- sh -c "mkdir test"
I've got a script that makes an arch lxc and turns it into a template.
And then bash scripts that deploys it with whatever custom stuff is needed (volume mounts, podman, files pushed into container etc).
Also a pacoloco server (arch/pacman cache) so that all the building and updating for everything is fast & not hitting the upstreams unnecessarily.
Terraform or Ansible also works for this but decided bash is ultimately less moving parts
