Documentation : Ensure FQDNs are used in Geo
In Geo, it's easy to forget to set a FQDN in the
external_url. If you also access the secondary without a FQDN, the OAuth
redirect_uri may also be invalid, causing an invalid redirect URI error. Users may accidentally do this if the internal name of the host resolves.
We should make this easier, either by enforcing a FQDN or documenting very clearly that this needs to be done.