[#196] Add GetObjectTagging

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

api/handler/get.go

@@ -65,7 +65,7 @@ func fetchRangeHeader(headers http.Header, fullSize uint64) (*layer.RangeParams,
 	return &layer.RangeParams{Start: start, End: end}, nil
 }
 
-func writeHeaders(h http.Header, info *layer.ObjectInfo) {
+func writeHeaders(h http.Header, info *layer.ObjectInfo, tagSetLength int) {
 	if len(info.ContentType) > 0 {
 		h.Set(api.ContentType, info.ContentType)
 	}
@@ -73,6 +73,7 @@ func writeHeaders(h http.Header, info *layer.ObjectInfo) {
 	h.Set(api.ContentLength, strconv.FormatInt(info.Size, 10))
 	h.Set(api.ETag, info.HashSum)
 	h.Set(api.AmzVersionID, info.ID().String())
+	h.Set(api.AmzTaggingCount, strconv.Itoa(tagSetLength))
 
 	for key, val := range info.Headers {
 		h[api.MetadataPrefix+key] = []string{val}
@@ -119,7 +120,14 @@ func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
 		h.logAndSendError(w, "could not parse range header", reqInfo, err)
 		return
 	}
-	writeHeaders(w.Header(), info)
+
+	tagSet, err := h.obj.GetObjectTagging(r.Context(), info)
+	if err != nil && !errors.IsS3Error(err, errors.ErrNoSuchKey) {
+		h.logAndSendError(w, "could not get object tag set", reqInfo, err)
+		return
+	}
+
+	writeHeaders(w.Header(), info, len(tagSet))
 	if params != nil {
 		writeRangeHeaders(w, params, info.Size)
 	}

api/handler/head.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/nspcc-dev/neofs-s3-gw/api"
+	"github.com/nspcc-dev/neofs-s3-gw/api/errors"
 	"github.com/nspcc-dev/neofs-s3-gw/api/layer"
 	"go.uber.org/zap"
 )
@@ -46,6 +47,11 @@ func (h *handler) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
 		h.logAndSendError(w, "could not fetch object info", reqInfo, err)
 		return
 	}
+	tagSet, err := h.obj.GetObjectTagging(r.Context(), inf)
+	if err != nil && !errors.IsS3Error(err, errors.ErrNoSuchKey) {
+		h.logAndSendError(w, "could not get object tag set", reqInfo, err)
+		return
+	}
 
 	if len(info.ContentType) == 0 {
 		buffer := bytes.NewBuffer(make([]byte, 0, sizeToDetectType))
@@ -62,7 +68,7 @@ func (h *handler) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
 		info.ContentType = http.DetectContentType(buffer.Bytes())
 	}
 
-	writeHeaders(w.Header(), info)
+	writeHeaders(w.Header(), info, len(tagSet))
 	w.WriteHeader(http.StatusOK)
 }
 

api/handler/tagging.go

@@ -60,6 +60,38 @@ func (h *handler) PutObjectTaggingHandler(w http.ResponseWriter, r *http.Request
 	}
 }
 
+func (h *handler) GetObjectTaggingHandler(w http.ResponseWriter, r *http.Request) {
+	reqInfo := api.GetReqInfo(r.Context())
+
+	p := &layer.HeadObjectParams{
+		Bucket:    reqInfo.BucketName,
+		Object:    reqInfo.ObjectName,
+		VersionID: reqInfo.URL.Query().Get("versionId"),
+	}
+
+	objInfo, err := h.obj.GetObjectInfo(r.Context(), p)
+	if err != nil {
+		h.logAndSendError(w, "could not get object info", reqInfo, err)
+		return
+	}
+
+	tagSet, err := h.obj.GetObjectTagging(r.Context(), objInfo)
+	if err != nil {
+		h.logAndSendError(w, "could not get object tagging", reqInfo, err)
+		return
+	}
+
+	tagging := &Tagging{}
+	for k, v := range tagSet {
+		tagging.TagSet = append(tagging.TagSet, Tag{Key: k, Value: v})
+	}
+
+	w.Header().Set(api.AmzVersionID, objInfo.Version())
+	if err = api.EncodeToResponse(w, tagging); err != nil {
+		h.logAndSendError(w, "something went wrong", reqInfo, err)
+	}
+}
+
 func checkTagSet(tagSet []Tag) error {
 	if len(tagSet) > 10 {
 		return errors.GetAPIError(errors.ErrInvalidTag)

api/handler/unimplemented.go

@@ -31,10 +31,6 @@ func (h *handler) AbortMultipartUploadHandler(w http.ResponseWriter, r *http.Req
 	h.logAndSendError(w, "not implemented", api.GetReqInfo(r.Context()), errors.GetAPIError(errors.ErrNotImplemented))
 }
 
-func (h *handler) GetObjectTaggingHandler(w http.ResponseWriter, r *http.Request) {
-	h.logAndSendError(w, "not implemented", api.GetReqInfo(r.Context()), errors.GetAPIError(errors.ErrNotImplemented))
-}
-
 func (h *handler) DeleteObjectTaggingHandler(w http.ResponseWriter, r *http.Request) {
 	h.logAndSendError(w, "not implemented", api.GetReqInfo(r.Context()), errors.GetAPIError(errors.ErrNotImplemented))
 }

api/headers.go

@@ -5,6 +5,7 @@ const (
 	MetadataPrefix       = "X-Amz-Meta-"
 	AmzMetadataDirective = "X-Amz-Metadata-Directive"
 	AmzVersionID         = "X-Amz-Version-Id"
+	AmzTaggingCount      = "X-Amz-Tagging-Count"
 
 	LastModified       = "Last-Modified"
 	Date               = "Date"

api/layer/layer.go

@@ -162,6 +162,7 @@ type (
 
 		GetObject(ctx context.Context, p *GetObjectParams) error
 		GetObjectInfo(ctx context.Context, p *HeadObjectParams) (*ObjectInfo, error)
+		GetObjectTagging(ctx context.Context, p *ObjectInfo) (map[string]string, error)
 
 		PutObject(ctx context.Context, p *PutObjectParams) (*ObjectInfo, error)
 		PutObjectTagging(ctx context.Context, p *PutTaggingParams) error
@@ -371,6 +372,32 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*ObjectInfo,
 	return n.objectPut(ctx, bkt, p)
 }
 
+// GetObjectTagging from storage.
+func (n *layer) GetObjectTagging(ctx context.Context, oi *ObjectInfo) (map[string]string, error) {
+	bktInfo := &BucketInfo{
+		Name:  oi.Bucket,
+		CID:   oi.CID(),
+		Owner: oi.Owner,
+	}
+
+	objInfo, err := n.getSystemObject(ctx, bktInfo, oi.TagsObject())
+	if err != nil && !errors.IsS3Error(err, errors.ErrNoSuchKey) {
+		return nil, err
+	}
+
+	var tagSet map[string]string
+	if objInfo != nil {
+		tagSet = make(map[string]string, len(objInfo.Headers))
+		for k, v := range objInfo.Headers {
+			if strings.HasPrefix(k, tagPrefix) {
+				tagSet[strings.TrimPrefix(k, tagPrefix)] = v
+			}
+		}
+	}
+
+	return tagSet, nil
+}
+
 // PutObjectTagging into storage.
 func (n *layer) PutObjectTagging(ctx context.Context, p *PutTaggingParams) error {
 	bktInfo := &cache.BucketInfo{
@@ -438,6 +465,20 @@ func (n *layer) putSystemObject(ctx context.Context, bktInfo *cache.BucketInfo,
 	return oid, nil
 }
 
+func (n *layer) getSystemObject(ctx context.Context, bkt *BucketInfo, objName string) (*ObjectInfo, error) {
+	oid, err := n.objectFindID(ctx, &findParams{cid: bkt.CID, attr: objectSystemAttributeName, val: objName})
+	if err != nil {
+		return nil, err
+	}
+
+	meta, err := n.objectHead(ctx, bkt.CID, oid)
+	if err != nil {
+		return nil, err
+	}
+
+	return objectInfoFromMeta(bkt, meta, "", ""), nil
+}
+
 // CopyObject from one bucket into another bucket.
 func (n *layer) CopyObject(ctx context.Context, p *CopyObjectParams) (*ObjectInfo, error) {
 	pr, pw := io.Pipe()

docs/aws_s3_compat.md

@@ -69,7 +69,7 @@ Should be supported soon.
 |    | Method              | Comments |
 |----|---------------------|----------|
 | 🔴 | DeleteObjectTagging |          |
-| 🔴 | GetObjectTagging    |          |
+| 🟢 | GetObjectTagging    |          |
 | 🟢 | PutObjectTagging    |          |
 
 ## Versioning