func()

in controllers/daemon/staticgatewayconfiguration_controller.go [510:568]
51 lines of code
15 McCabe index (conditional complexity)

func (r *StaticGatewayConfigurationReconciler) reconcileIlbIPOnHost(ctx context.Context, ilbIP string) error {
	log := log.FromContext(ctx)
	eth0, err := r.Netlink.LinkByName("eth0")
	if err != nil {
		return fmt.Errorf("failed to retrieve link eth0: %w", err)
	}

	if len(nodeMeta.Network.Interface) == 0 || len(nodeMeta.Network.Interface[0].IPv4.Subnet) == 0 {
		return fmt.Errorf("imds does not provide subnet information about the node")
	}
	prefix, err := strconv.Atoi(nodeMeta.Network.Interface[0].IPv4.Subnet[0].Prefix)
	if err != nil {
		return fmt.Errorf("failed to retrieve and parse prefix: %w", err)
	}

	addresses, err := r.Netlink.AddrList(eth0, nl.FAMILY_ALL)
	if err != nil {
		return fmt.Errorf("failed to retrieve IP addresses for eth0: %w", err)
	}

	if ilbIP == "" {
		// cleanup process
		for _, address := range addresses {
			if address.Label == consts.ILBIPLabel {
				log.Info("Removing ILB IP from eth0", "ilb IP", address.IPNet.String())
				if err := r.Netlink.AddrDel(eth0, &address); err != nil {
					return fmt.Errorf("failed to delete ILB IP from eth0: %w", err)
				}
			}
		}
		return nil
	}

	ilbIpCidr := fmt.Sprintf("%s/%d", ilbIP, prefix)
	ilbIpNet, err := netlink.ParseIPNet(ilbIpCidr)
	if err != nil {
		return fmt.Errorf("failed to parse ILB IP address: %s", ilbIpCidr)
	}

	addressPresent := false
	for _, address := range addresses {
		if address.IPNet.IP.Equal(ilbIpNet.IP) {
			addressPresent = true
			break
		}
	}

	if !addressPresent {
		log.Info("Adding ILB IP to eth0", "ilb IP", ilbIpCidr)
		if err := r.Netlink.AddrAdd(eth0, &netlink.Addr{
			IPNet: ilbIpNet,
			Label: consts.ILBIPLabel,
		}); err != nil {
			return fmt.Errorf("failed to add ILB IP to eth0: %w", err)
		}
	}

	return nil
}