GET Object Attributes¶

The GET Object Attributes operation returns a subset of object metadata without fetching the object itself. This operation is useful to quickly retrieve specific information about an object, such as its ETag, ObjectParts, StorageClass, and ObjectSize, without the overhead of a full GET or HEAD request.

ARTESCA extends this functionality to support the retrieval of user-defined metadata using the x-amz-meta-* and x-amz-meta-<key> attributes.

Requests¶

Syntax¶

GET /{{ObjectName}}?attributes HTTP/1.1
Host: {{BucketName}}.{{StorageService}}.com
Authorization: {{authorizationString}}
Date: {{date}}
x-amz-expected-bucket-owner: {{ExpectedBucketOwner}}
x-amz-object-attributes: {{ObjectAttributes}}

Parameters¶

Parameter

Type

Description

versionId

string

The version ID of the object whose attributes are being requested.

Default: None

Headers¶

The GET Object Attributes operation uses the following request headers in addition to those that are common to all operations (refer to Common Request Headers).

Header

Type

Description

x-amz-object-attributes

string

Specifies the attributes to return. Attribute names are comma-separated.

x-amz-meta-* returns all user-defined metadata for the object. x-amz-meta-<key> returns a specific user metadata key. These are Scality extensions not available in the standard S3 API.

Required: Yes

Note

User metadata values concern only user metadata, not tagging.

Note

When using x-amz-meta-* or x-amz-meta-<key>, the scality:GetObject\ AttributesCustom permission is required in addition to s3:GetObjectAttributes.

x-amz-expected-bucket-owner

string

The account ID of the expected bucket owner. If the bucket is owned by a different account, the request fails with the HTTP status code 403 Forbidden (access denied).

Default: None

Note

The AWS Checksum attribute is not supported by ARTESCA. Requesting Checksum in the x-amz-object-attributes header will result in a 501 Not Implemented response error.

Elements¶

The GET Object Attributes operation does not use request elements.

Responses¶

Headers¶

Header

Type

Description

x-amz-delete-marker

Boolean

Specifies whether the object is a delete marker.

Valid Values: true | false

x-amz-version-id

string

The version ID of the object.

Default: None

Last-Modified

string

The date and time at which the object was last modified.

Default: None

Elements¶

The GET Object Attributes operation returns an XML response body with the following elements.

Element	Type	Description
`GetObjectAttributesResponse`	Container	Root element for the response.
`ETag`	string	The entity tag of the object.
`ObjectParts`	Container	A collection of parts associated with a multipart upload.
`ObjectParts.PartsCount`	integer	The total number of parts.
`StorageClass`	string	The storage class of the object.
`ObjectSize`	integer	The size of the object in bytes.
`x-amz-meta-<key>`	string	User-defined metadata keys and values. These elements are only returned when the `x-amz-object-attributes` request header includes `x-amz-meta-*` (for all metadata) or `x-amz-meta-<key>` (for a specific key). Note This is a Scality extension.

Errors¶

Error	HTTP Code	Description
`InvalidRequest`	400	The `x-amz-object-attributes` header is missing or empty.
`InvalidArgument`	400	An invalid value was provided for `x-amz-object-attributes`.
`AccessDenied`	403	Access denied. Verify that the requester has the `s3:GetObjectAttributes` permission (and `scality:GetObjectAttributesCustom` when requesting user-defined metadata).
`NoSuchKey`	404	The specified object does not exist.
`NoSuchVersion`	404	The specified `versionId` does not exist.
`MethodNotAllowed`	405	The specified object is a delete marker.
`NotImplemented`	501	The `Checksum` attribute was requested but is not supported.

Examples¶

Getting Object Attributes¶

Request¶

GET /my-object?attributes HTTP/1.1
Host: {{bucketName}}.s3.example.com
Date: Wed, 28 Oct 2009 22:32:00 GMT
Authorization: {{authorizationString}}
x-amz-object-attributes: ETag,ObjectSize,StorageClass

Response¶

HTTP/1.1 200 OK
x-amz-id-2: eftixk72aD6Ap51TnqcoF8eFidJG9Z/2
x-amz-request-id: 318BC8BC148832E5
Date: Wed, 28 Oct 2009 22:32:00 GMT
Last-Modified: Wed, 12 Oct 2009 17:50:00 GMT
Content-Type: application/xml
Server: ScalityS3

<?xml version="1.0" encoding="UTF-8"?>
<GetObjectAttributesResponse>
  <ETag>fba9dede5f27731c9771645a39863328</ETag>
  <StorageClass>STANDARD</StorageClass>
  <ObjectSize>434234</ObjectSize>
</GetObjectAttributesResponse>

Getting Object Attributes for a Multipart-Uploaded Object¶

Request¶

GET /my-multipart-object?attributes HTTP/1.1
Host: {{bucketName}}.s3.example.com
Date: Wed, 28 Oct 2009 22:32:00 GMT
Authorization: {{authorizationString}}
x-amz-object-attributes: ObjectParts,ObjectSize

Response¶

HTTP/1.1 200 OK
x-amz-id-2: eftixk72aD6Ap51TnqcoF8eFidJG9Z/2
x-amz-request-id: 318BC8BC148832E5
Date: Wed, 28 Oct 2009 22:32:00 GMT
Last-Modified: Sun, 1 Jan 2006 12:00:00 GMT
Content-Type: application/xml
Server: ScalityS3

<?xml version="1.0" encoding="UTF-8"?>
<GetObjectAttributesResponse>
  <ObjectSize>209715200</ObjectSize>
  <ObjectParts>
    <PartsCount>5</PartsCount>
  </ObjectParts>
</GetObjectAttributesResponse>

Getting Attributes of a Specific Version of an Object¶

Request¶

GET /my-object?attributes&versionId=3/L4kqtJlcpXroDTDmpUMLUo HTTP/1.1
Host: {{bucketName}}.s3.example.com
Date: Wed, 28 Oct 2009 22:32:00 GMT
Authorization: {{authorizationString}}
x-amz-object-attributes: ETag,ObjectSize,StorageClass

Response¶

HTTP/1.1 200 OK
x-amz-id-2: eftixk72aD6Ap51TnqcoF8eFidJG9Z/2
x-amz-request-id: 318BC8BC148832E5
Date: Wed, 28 Oct 2009 22:32:00 GMT
Last-Modified: Sun, 1 Jan 2006 12:00:00 GMT
x-amz-version-id: 3/L4kqtJlcpXroDTDmJ+rmSpXd3QBpUMLUo
Content-Type: application/xml
Server: ScalityS3

<?xml version="1.0" encoding="UTF-8"?>
<GetObjectAttributesResponse>
  <ETag>fba9dede5f27731c9771645a39863328</ETag>
  <StorageClass>STANDARD</StorageClass>
  <ObjectSize>434234</ObjectSize>
</GetObjectAttributesResponse>

Getting Object Attributes with User-Defined Metadata¶

This example uses the x-amz-meta-* Scality extension value in the x-amz-object-attributes header to retrieve user-defined metadata along with standard object attributes.

Request¶

GET /my-object?attributes HTTP/1.1
Host: {{bucketName}}.s3.example.com
Date: Wed, 28 Oct 2009 22:32:00 GMT
Authorization: {{authorizationString}}
x-amz-object-attributes: ETag,ObjectSize,StorageClass,x-amz-meta-*

Response¶

HTTP/1.1 200 OK
x-amz-id-2: eftixk72aD6Ap51TnqcoF8eFidJG9Z/2
x-amz-request-id: 318BC8BC148832E5
Date: Wed, 28 Oct 2009 22:32:00 GMT
Last-Modified: Wed, 12 Oct 2009 17:50:00 GMT
Content-Type: application/xml
Server: ScalityS3

<?xml version="1.0" encoding="UTF-8"?>
<GetObjectAttributesResponse>
  <ETag>fba9dede5f27731c9771645a39863328</ETag>
  <StorageClass>STANDARD</StorageClass>
  <ObjectSize>434234</ObjectSize>
  <x-amz-meta-department>Legal</x-amz-meta-department>
  <x-amz-meta-project>compliance-2026</x-amz-meta-project>
</GetObjectAttributesResponse>