Kubernetes Ingress Controllers for HAProxy already exist. A nice one is at https://github.com/jcmoraisjr/haproxy-ingress Other examples of usage are spread around in the examples section of the ingress repo, like here https://github.com/kubernetes/ingress/tree/master/examples/d...

The DNS-SD code will ship with HAProxy 1.8, and we will gladly help out by adding it to the above ingress controller after the release. A WIP of that code is up on github in case you’re interested. In fact, HAProxy is full of surprises and little known features (like the dynamic scaling via haproxy runtime api we already contributed to the controller) and we're happy to share them with everyone!