There has been periodic interest expressed in installing IPA on a SoC computer like the Raspberry or Banana Pi. While technically possible there are a number of caveats.
We do not have specific SoC recommendations but in general the minimum requirements are 2 GB of RAM with a CA-full install and 1 GB RAM with a CA-less or a replica without a CA installed. We have no figures on how well, if at all, this will scale.
SoC chips tend to have SDcard-based disks which are slow. This can cause service timeouts during installation. One way to mitigate this is to create /etc/ipa/installer.conf prior to calling ipa-server-install:
$ cat /etc/ipa/installer.conf [global] startup_timeout=900
Note that it isn't uncommon for the CA to take 10 minutes or more to start on a Pi.
A user contributed his experience installing IPA on a BananaPi at HowTo/FreeIPA_on_banana_pi
Revised: Feb 1, 2018