Right that's how everything else we have is setup. For this situation though right now they're just using LTMs in separate datacenters. There is an A record that points to a VIP in the datacenter that is active and for a disaster recovery situation DNS would be changed to point the record to the VIP in the other datacenter. The DNS records are wildcarded *.datacenter.domain.com to 1.1.1.1 and that resolved to a VIP with the openshift routers as the pool members. Based on the application.something part of the URL Openshift knows where to route the traffic.
For this they want the developers to have a singular URL for their apps that wouldn't have to be changed in a true disaster or just a disaster recovery exercise so that would be their application.gtm.domain.com. There would be a separate WIP for each. So in a disaster situation we would just disable the pool member on the GTM for the datacenter that they weren't running out of.
The openshift configuration needs to have a route configured to know which application is being called. Right now thats the application.something.datacenter.domain.com and those engineers don't want to have to add another route (the gtm.domain.com) for each application. This is all internal traffic not exposed to the internet.
It isn't going to be a hot/hot scenerio but we wanted the developers to have one URL, traffic to know which datacenter based on the pool member enabled on the wide IP but then when it gets to the VIP on the LTM change the URL ending so that openshift still see the route and knows where to send the traffic.
When we do disaster recovery exercises not all of the applications do it at the same time so we need to be able to send some traffic to one datacenter or the other.