How to change "svc.cluster.local" internal domain

I need to be able to create containers that have to register thamselves to a FreeIPA server and this requires them to have a proper FQDN that my FreeIPA, that is outside the rancher environment can resolve.
The solution could be to make the internal domain coherent with the known domain.
How can I change the svc.cluster.local to something like mydomain.org?
Thanks
Luca