hello-go/grpc-demo/deploy/gateway_backend.yaml

---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: grpc-example
  namespace: prd
spec:
  hosts:
  - grpc-example
  http:
  - route:
    - destination:
        host: grpc-example
        subset: v1
        port:
          number: 50051
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: http-backend
  namespace: prd
spec:
  hosts:
  - http-backend
  http:
  - route:
    - destination:
        host: http-backend
        subset: v1
        port:
          number: 8080