Mycelium network is a Open source full features SDN platform. MNP will be the best production grade platform of SDN
K8s Operator
https://github.com/yucs/yucs-awesome-resource
https://github.com/yucs/yucs-awesome-resource/blob/master/kubernetes/2017-12-21-operator.md
https://engineering.bitnami.com/articles/kubewatch-an-example-of-kubernetes-custom-controller.html