1. Create new machine - manually type in wanted IP.
2. Install docker in VM, which creates interface docker0
3. Edit machine in Foreman

This results in Foreman setting ip 172.x in the GUI - which doesn't match subnet, DNS or DHCP option. Trying to save your edited host results in DHCP conflict - which it's unable to resolve since 172.x is not a valid subnet in DHCP.

Manually typing the correct IP address also doesn't solve this, as Foreman still attempts to save using the 172.x as seen by facter.

Foreman should simply ignore facter with regards to IP, and always use the user inputted value.