func()

in google_guest_agent/network/manager/netplan_linux.go [571:636]

• 49 lines of code
• 12 McCabe index (conditional complexity)

func (n *netplan) rollbackVlanNics(ctx context.Context, nics *Interfaces) (bool, error) {
	var deleteNics []string
	var deleteDirs []string

	if len(nics.VlanInterfaces) == 0 {
		logger.Debugf("No VLAN interfaces in args, skipping rollback")
		return false, nil
	}

	existingVlanCfgs := netplanDropin{}
	netplanVlanDropinFile := n.dropinFile(netplanVlanSuffix)
	// There's no config file per interface, single netplan config file lists all the interfaces.
	if utils.FileExists(netplanVlanDropinFile, utils.TypeFile) {
		if err := readYamlFile(netplanVlanDropinFile, &existingVlanCfgs); err != nil {
			return false, fmt.Errorf("unable to read %q trying rollback configs: %w", netplanVlanDropinFile, err)
		}
	}

	for _, iface := range nics.VlanInterfaces {
		ifaceName := n.vlanInterfaceName(iface.ParentInterfaceID, iface.VlanInterface.Vlan)
		key := n.ID(ifaceName)

		deleteNics = append(deleteNics, key)
		delete(existingVlanCfgs.Network.Vlans, key)

		dropin := filepath.Join(n.networkdDropinDir, fmt.Sprintf("10-netplan-%s.network.d", key))
		if utils.FileExists(dropin, utils.TypeDir) {
			// Networkd dropin is a directory for each interface with override.conf file.
			// Remove should delete the complete directory instead of that one file.
			deleteDirs = append(deleteDirs, dropin)
		}
	}

	logger.Infof("Deleting VLAN NICs: %v", deleteNics)
	// Simply removing configs on disk and reloading netplan/networkctl doesn't remove
	// existing vlan nics, it requires instance reboot or systemd-networkd restart. Instead,
	// make sure its removed by [networkctl delete <interfaces>] command.
	args := []string{"delete"}
	args = append(args, deleteNics...)
	if err := run.Quiet(ctx, "networkctl", args...); err != nil {
		return false, fmt.Errorf("networkctl %v failed with error: %w", args, err)
	}

	// If no more VLANs exist simply remove the file.
	if len(existingVlanCfgs.Network.Vlans) == 0 {
		logger.Infof("Removing %s dropin file for vlan rollback", netplanVlanDropinFile)
		if err := os.Remove(netplanVlanDropinFile); err != nil {
			return false, fmt.Errorf("unable to remove netplan vlan dropin (%s): %w", netplanVlanDropinFile, err)
		}
	} else {
		logger.Infof("Updating %s dropin file for vlan rollback", netplanVlanDropinFile)
		// Otherwise, overwrite configs to reflect expected interfaces.
		if _, err := n.write(existingVlanCfgs, netplanVlanSuffix); err != nil {
			return false, fmt.Errorf("unable to update vlan config at (%s): %w", netplanVlanDropinFile, err)
		}
	}

	logger.Infof("Removing directories %v as part of vlan rollback", deleteDirs)
	for _, dir := range deleteDirs {
		if err := os.RemoveAll(dir); err != nil {
			return false, fmt.Errorf("unable to remove directory %q: %w", dir, err)
		}
	}

	return true, nil
}