feat: adds x-amz-tagging-count support for HeadObject

Closes #1346

`GetObject` and `HeadObject` return the `x-amz-tagging-count` header in the response, which specifies the number of tags associated with the object. This was already supported for `GetObject`, but missing for `HeadObject`. This implementation adds support for `HeadObject` in `azure` and `posix` and updates the integration tests to cover this functionality for `GetObject`.

backend/azure/azure.go

@@ -583,6 +583,11 @@ func (az *Azure) HeadObject(ctx context.Context, input *s3.HeadObjectInput) (*s3
 		}
 	}
 
+	if resp.TagCount != nil {
+		tagcount := int32(*resp.TagCount)
+		result.TagCount = &tagcount
+	}
+
 	return result, nil
 }
 

backend/posix/posix.go

@@ -4026,6 +4026,16 @@ func (p *Posix) HeadObject(ctx context.Context, input *s3.HeadObjectInput) (*s3.
 		}
 	}
 
+	var tagCount *int32
+	tags, err := p.getAttrTags(bucket, object, versionId)
+	if err != nil && !errors.Is(err, s3err.GetAPIError(s3err.ErrBucketTaggingNotFound)) {
+		return nil, err
+	}
+	if tags != nil {
+		tc := int32(len(tags))
+		tagCount = &tc
+	}
+
 	return &s3.HeadObjectOutput{
 		ContentLength:             &length,
 		AcceptRanges:              backend.GetPtrFromString("bytes"),
@@ -4050,6 +4060,7 @@ func (p *Posix) HeadObject(ctx context.Context, input *s3.HeadObjectInput) (*s3.
 		ChecksumSHA256:            checksums.SHA256,
 		ChecksumCRC64NVME:         checksums.CRC64NVME,
 		ChecksumType:              cType,
+		TagCount:                  tagCount,
 	}, nil
 }
 

s3api/controllers/object-head.go

@@ -150,6 +150,7 @@ func (c S3ApiController) HeadObject(ctx *fiber.Ctx) (*Response, error) {
 			"x-amz-storage-class":                 utils.ConvertToStringPtr(res.StorageClass),
 			"x-amz-checksum-type":                 utils.ConvertToStringPtr(res.ChecksumType),
 			"x-amz-object-lock-retain-until-date": utils.FormatDatePtrToString(res.ObjectLockRetainUntilDate, time.RFC3339),
+			"x-amz-tagging-count":                 utils.ConvertPtrToStringPtr(res.TagCount),
 		},
 		MetaOpts: &MetaOptions{
 			BucketOwner: parsedAcl.Owner,

s3api/controllers/object-head_test.go

@@ -147,6 +147,7 @@ func TestS3ApiController_HeadObject(t *testing.T) {
 						"x-amz-checksum-type":                 nil,
 						"x-amz-object-lock-retain-until-date": nil,
 						"Last-Modified":                       nil,
+						"x-amz-tagging-count":                 nil,
 						"Content-Type":                        utils.GetStringPtr("application/xml"),
 						"Content-Length":                      utils.GetStringPtr("100"),
 					},

tests/integration/GetObject.go

@@ -527,6 +527,7 @@ func GetObject_success(s *S3Conf) error {
 			Expires:            &expires,
 			CacheControl:       &cacheControl,
 			Metadata:           meta,
+			Tagging:            getPtr("key=value&key1=val1"),
 		}, s3client)
 		if err != nil {
 			return err
@@ -577,6 +578,13 @@ func GetObject_success(s *S3Conf) error {
 			return fmt.Errorf("expected the object metadata to be %v, instead got %v",
 				meta, out.Metadata)
 		}
+		var tagCount int32
+		if out.TagCount != nil {
+			tagCount = *out.TagCount
+		}
+		if tagCount != 2 {
+			return fmt.Errorf("expected tag count to be 2, instead got %v", tagCount)
+		}
 
 		bdy, err := io.ReadAll(out.Body)
 		if err != nil {

tests/integration/HeadObject.go

@@ -566,6 +566,7 @@ func HeadObject_success(s *S3Conf) error {
 			ContentLanguage:    &cLang,
 			CacheControl:       &cacheControl,
 			Expires:            &expires,
+			Tagging:            getPtr("key=value"),
 		}, s3client)
 		if err != nil {
 			return err
@@ -620,6 +621,14 @@ func HeadObject_success(s *S3Conf) error {
 			return fmt.Errorf("expected the storage class to be %v, instead got %v",
 				types.StorageClassStandard, out.StorageClass)
 		}
+		tagCount := int32(0)
+		if out.TagCount != nil {
+			tagCount = *out.TagCount
+		}
+
+		if tagCount != 1 {
+			return fmt.Errorf("expected the tagcount to be 1, instead got %v", tagCount)
+		}
 
 		return nil
 	})