Poettering: Factory Reset, Stateless Systems, Reproducible Systems & Verifiable Systems

Here is one method:

Use DHCP to assign a domain to the system so the machine can use DNS to look up the services you need to configure the system.

The service can supply machine specific information.

An other method is what is already used which is cloudinit.

It is used with virtual machines a lot, but can also be used with bare metal. Cloudinit is automatically started at startup and talks to a well-know local-link IP-address on the network. Usually using HTTP on 169.254.169.254.