// FakeNetwork implements the NetworkInterfacer interface for test purpose.
type FakeNetwork struct {
	NetworkInterfaces []net.Interface
	// The key of map Addrs is the network interface name
	Address map[string][]net.Addr
}

// NewFakeNetwork initializes a FakeNetwork.
func NewFakeNetwork() *FakeNetwork {
	return &FakeNetwork{
		NetworkInterfaces: make([]net.Interface, 0),
		Address:           make(map[string][]net.Addr),
	}
}

#  IP_ALIAS_SUBNETWORK
function detect-k8s-subnetwork() {
  local subnetwork_url
  subnetwork_url=$(gcloud compute instances describe \
    "${KUBE_MASTER}" --project="${PROJECT}" --zone="${ZONE}" \
    --format='value(networkInterfaces[0].subnetwork)')
  if [[ -n ${subnetwork_url} ]]; then
    IP_ALIAS_SUBNETWORK=${subnetwork_url##*/}
  fi
}

# Set IP_ALIAS_SUBNETWORK's allowSubnetCidrRoutesOverlap to a boolean value.