provider/dyn.go
func (d *dynProviderState) ApplyChanges(changes *plan.Changes) error {
	log.Debugf("Processing chages: %+v", changes)

	if d.DryRun {
		log.Infof("Will NOT delete these records: %+v", changes.Delete)
		log.Infof("Will NOT create these records: %+v", changes.Create)
		log.Infof("Will NOT update these records: %+v", merge(changes.UpdateOld, changes.UpdateNew))
		return nil
	}

	client, err := d.login()
	if err != nil {
		return err
	}
	defer client.Logout()

	var errs []error

	needsCommit := false

	for _, ep := range changes.Delete {
		err := d.deleteRecord(client, ep)
		if err != nil {
			errs = append(errs, err)
		} else {
			needsCommit = true
		}
	}

	for _, ep := range changes.Create {
		err := d.createRecord(client, ep)
		if err != nil {
			errs = append(errs, err)
		} else {
			needsCommit = true
		}
	}

	updates := merge(changes.UpdateOld, changes.UpdateNew)
	log.Debugf("Updates after merging: %+v", updates)
	for _, ep := range updates {
		err := d.replaceRecord(client, ep)
		if err != nil {
			errs = append(errs, err)
		} else {
			needsCommit = true
		}
	}

	switch len(errs) {
	case 0:
	case 1:
		return errs[0]
	default:
		return fmt.Errorf("Multiple errors committing: %+v", errs)
	}

	if needsCommit {
		return d.commit(client)
	}

	return nil
}
func (d *dynProviderState) ApplyChanges(changes *plan.Changes) error {
	log.Debugf("Processing chages: %+v", changes)

	if d.DryRun {
		log.Infof("Will NOT delete these records: %+v", changes.Delete)
		log.Infof("Will NOT create these records: %+v", changes.Create)
		log.Infof("Will NOT update these records: %+v", merge(changes.UpdateOld, changes.UpdateNew))
		return nil
	}

	client, err := d.login()
	if err != nil {
		return err
	}
	defer client.Logout()

	var errs []error

	needsCommit := false

	for _, ep := range changes.Delete {
		err := d.deleteRecord(client, ep)
		if err != nil {
			errs = append(errs, err)
		} else {
			needsCommit = true
		}
	}

	for _, ep := range changes.Create {
		err := d.createRecord(client, ep)
		if err != nil {
			errs = append(errs, err)
		} else {
			needsCommit = true
		}
	}

	updates := merge(changes.UpdateOld, changes.UpdateNew)
	log.Debugf("Updates after merging: %+v", updates)
	for _, ep := range updates {
		err := d.replaceRecord(client, ep)
		if err != nil {
			errs = append(errs, err)
		} else {
			needsCommit = true
		}
	}

	switch len(errs) {
	case 0:
	case 1:
		return errs[0]
	default:
		return fmt.Errorf("Multiple errors committing: %+v", errs)
	}

	if needsCommit {
		return d.commit(client)
	}

	return nil
}
// this method does C + 2*Z requests: C=total number of changes, Z = number of
// affected zones (1 login + 1 commit)