code: func gatherAllHostports(activePodPortMappings []*PodPortMapping) (map[*PortMapping]targetPod, error) {
  	podHostportMap := make(map[*PortMapping]targetPod)
  	for _, pm := range activePodPortMappings {
  		if pm.IP.To4() == nil {
  			return nil, fmt.Errorf("Invalid or missing pod %s IP", getPodFullName(pm))
  		}
  		// should not handle hostports for hostnetwork pods
  		if pm.HostNetwork {
  			continue
  		}
  
  		for _, port := range pm.PortMappings {
  			if port.HostPort != 0 {
  				podHostportMap[port] = targetPod{podFullName: getPodFullName(pm), podIP: pm.IP.String()}
  			}
  		}
  	}
  	return podHostportMap, nil
  }
docs: // gatherAllHostports returns all hostports that should be presented on node,
  // given the list of pods running on that node and ignoring host network
  // pods (which don't need hostport <-> container port mapping).