frostfs-s3-gw/api/layer/notifications.go

package layer

import (
	"bytes"
	"context"
	"encoding/xml"
	"io"

	"github.com/google/uuid"
	"github.com/nspcc-dev/neofs-s3-gw/api/data"
	"github.com/nspcc-dev/neofs-s3-gw/api/errors"
	"go.uber.org/zap"
)

type (
	PutBucketNotificationConfigurationParams struct {
		BktInfo *data.BucketInfo
		Reader  io.Reader
	}
)

func (n *layer) PutBucketNotificationConfiguration(ctx context.Context, p *PutBucketNotificationConfigurationParams) error {
	if !n.IsNotificationEnabled() {
		return errors.GetAPIError(errors.ErrNotificationNotEnabled)
	}

	var (
		buf       bytes.Buffer
		tee       = io.TeeReader(p.Reader, &buf)
		conf      = &data.NotificationConfiguration{}
		completed bool
		err       error
	)

	if err = xml.NewDecoder(tee).Decode(conf); err != nil {
		return errors.GetAPIError(errors.ErrMalformedXML)
	}

	if completed, err = n.checkAndCompleteNotificationConfiguration(conf); err != nil {
		return err
	}
	if completed {
		confXML, err := xml.Marshal(conf)
		if err != nil {
			return err
		}
		buf.Reset()
		buf.Write(confXML)
	}

	s := &PutSystemObjectParams{
		BktInfo:  p.BktInfo,
		ObjName:  p.BktInfo.NotificationConfigurationObjectName(),
		Metadata: map[string]string{},
		Prefix:   "",
		Reader:   &buf,
	}

	obj, err := n.putSystemObjectIntoNeoFS(ctx, s)
	if err != nil {
		return err
	}

	if obj.Size == 0 && !conf.IsEmpty() {
		return errors.GetAPIError(errors.ErrInternalError)
	}

	if err = n.systemCache.PutNotificationConfiguration(systemObjectKey(p.BktInfo, s.ObjName), conf); err != nil {
		n.log.Error("couldn't cache system object", zap.Error(err))
	}

	return nil
}

func (n *layer) GetBucketNotificationConfiguration(ctx context.Context, bktInfo *data.BucketInfo) (*data.NotificationConfiguration, error) {
	if !n.IsNotificationEnabled() {
		return nil, errors.GetAPIError(errors.ErrNotificationNotEnabled)
	}
	conf, err := n.getNotificationConf(ctx, bktInfo, bktInfo.NotificationConfigurationObjectName())
	if err != nil {
		if errors.IsS3Error(err, errors.ErrNoSuchKey) {
			return &data.NotificationConfiguration{}, nil
		}
		return nil, err
	}

	return conf, nil
}

func (n *layer) getNotificationConf(ctx context.Context, bkt *data.BucketInfo, sysName string) (*data.NotificationConfiguration, error) {
	if conf := n.systemCache.GetNotificationConfiguration(systemObjectKey(bkt, sysName)); conf != nil {
		return conf, nil
	}

	obj, err := n.getSystemObjectFromNeoFS(ctx, bkt, sysName)
	if err != nil {
		return nil, err
	}

	conf := &data.NotificationConfiguration{}

	if err = xml.Unmarshal(obj.Payload(), &conf); err != nil {
		return nil, err
	}

	if err = n.systemCache.PutNotificationConfiguration(systemObjectKey(bkt, sysName), conf); err != nil {
		n.log.Warn("couldn't put system meta to objects cache",
			zap.Stringer("object id", obj.ID()),
			zap.Stringer("bucket id", bkt.CID),
			zap.Error(err))
	}

	return conf, nil
}

func (n *layer) checkAndCompleteNotificationConfiguration(c *data.NotificationConfiguration) (completed bool, err error) {
	if c == nil {
		return
	}

	if c.TopicConfigurations != nil || c.LambdaFunctionConfigurations != nil {
		return completed, errors.GetAPIError(errors.ErrNotificationTopicNotSupported)
	}

	for i, q := range c.QueueConfigurations {
		if err = checkEvents(q.Events); err != nil {
			return
		}
		if q.ID == "" {
			completed = true
			c.QueueConfigurations[i].ID = uuid.NewString()
		}
	}

	return
}

func checkEvents(events []string) error {
	for _, e := range events {
		if _, ok := data.ValidEvents[e]; !ok {
			return errors.GetAPIError(errors.ErrEventNotification)
		}
	}

	return nil
}