func()

in google_guest_agent/network/manager/wicked_linux.go [119:171]

• 42 lines of code
• 7 McCabe index (conditional complexity)

func (n *wicked) SetupVlanInterface(ctx context.Context, cfg *cfg.Sections, nics *Interfaces) error {
	var keepMe []string

	// Make sure the dhclient route priority is in a different range of ethernet nics.
	priority := 20200

	for _, curr := range nics.VlanInterfaces {
		iface := fmt.Sprintf("gcp.%s.%d", curr.ParentInterfaceID, curr.Vlan)

		configLines := []string{
			googleComment,
			"BOOTPROTO=dhcp", // NOTE: 'dhcp' is the dhcp4+dhcp6 option.
			"VLAN=yes",
			"ETHTOOL_OPTIONS=reorder_hdr off",
			fmt.Sprintf("DEVICE=%s", iface),
			fmt.Sprintf("MTU=%d", curr.MTU),
			fmt.Sprintf("LLADDR=%s", curr.Mac),
			fmt.Sprintf("ETHERDEVICE=%s", curr.ParentInterfaceID),
			fmt.Sprintf("VLAN_ID=%d", curr.Vlan),
			fmt.Sprintf("DHCLIENT_ROUTE_PRIORITY=%d", priority),
		}

		ifcfg, err := os.Create(n.ifcfgFilePath(iface))
		if err != nil {
			return fmt.Errorf("failed to create vlan's ifcfg file: %+v", err)
		}

		content := strings.Join(configLines, "\n")
		writeLen, err := ifcfg.WriteString(content)
		if err != nil {
			return fmt.Errorf("error writing vlan's icfg file for %s: %v", iface, err)
		}

		contentLen := len(content)
		if writeLen != contentLen {
			return fmt.Errorf("error writing vlan's ifcfg file, wrote %d bytes, config content size is %d bytes",
				writeLen, contentLen)
		}

		if err = run.Quiet(ctx, n.wickedCommand, "ifup", iface); err != nil {
			return fmt.Errorf("error enabling vlan's interfaces: %v", err)
		}

		priority += 100
		keepMe = append(keepMe, iface)
	}

	if err := n.cleanupVlanInterfaces(ctx, keepMe); err != nil {
		return fmt.Errorf("failed to cleanup vlan interfaces: %+v", err)
	}

	return nil
}