Also see Project Calico for containers, they use the linux kernel as FIB, but obviously they could just as well use OpenFlow to program switches for bare metal machines (which then might run containers).
This is very different than a TOR switch or core-router running OpenFlow. Only a few places are running more than a couple thousand VMs in a single SDN, and its nothing like what is being discussed above.
But if you need the big guns there are a ton of OpenStack Neutron plugins, OpenDaylight being one of them (networking-odl) and there are the classical/traditional vendor ones (Cisco, Arista, and so on).
I think the future is very much means this jungle of APIs integrating in whatever tangled ways, and eventually the reliable, robust and sane ones will prevail.