code: func getListenIPPortMap(service *v1.Service, listenPort int, nodePort int) map[string]int {
  	listenIPPortMap := make(map[string]int)
  	listenIPPortMap[service.Spec.ClusterIP] = listenPort
  
  	for _, ip := range service.Spec.ExternalIPs {
  		listenIPPortMap[ip] = listenPort
  	}
  
  	for _, ingress := range service.Status.LoadBalancer.Ingress {
  		listenIPPortMap[ingress.IP] = listenPort
  	}
  
  	if nodePort != 0 {
  		listenIPPortMap[allAvailableInterfaces] = nodePort
  	}
  
  	return listenIPPortMap
  }
docs: // getListenIPPortMap returns a slice of all listen IPs for a service.