Removal of Central Mode code

[Tim Rozet]

Heads up OVN-Kubernetes users,

We announced deprecation of central mode for OVN-Kubernetes in 1.2. 1.3 released last week and still allows central mode to be used. We are about to remove all code related to Central mode in the master branch:

https://github.com/ovn-kubernetes/ovn-kubernetes/pull/6303

1.4 will deploy as Interconnect (IC) mode only. IC provides a more scalable architecture and has been tested and used in production for several years now. Please ensure you have a transition plan in place to move to IC for that release. There is no supported, automated upgrade although with manual steps one can migrate a cluster with some downtime (cluster in maintenance mode). We will provide some documentation indicating the manual steps on the website.

Thanks,

-Tim