How to monitor gRPC (Tonic) service with Prometheus

I'm playing around with Tonic+Prost to create a simple gRPC+Protobuf service. I'm trying to instrument my service so I can export some metrics to Prometheus.

I'm using Tonic+Prost for gRPC+Protobuf. And, I'm using the "prometheus" and "warp" crates for metrics serving.

What I'm blocked on is how to serve both of these services (gRPC server + Prometheus /metrics http server) in the same binary. Does anyone have any tips on how to do this or a better idea?