There is a `--no-install` flag on both `uc machine init` and `uc machine add` that skips that `curl | bash` install step.

You need to prepare the machine some other way first then, but it's just installing docker and the uncloud service.

I use the `--no-install` option with my own cluster, as I have my own pre-provisioning process that includes some additional setup beyond the docker/uncloud elements.