S3 / Client / get_object_attributes

get_object_attributes#

S3.Client.get_object_attributes(**kwargs)#

Retrieves all the metadata from an object without returning the object itself. This operation is useful if you’re interested only in an object’s metadata.

GetObjectAttributes combines the functionality of HeadObject and ListParts. All of the data returned with each of those individual calls can be returned with a single call to GetObjectAttributes.

Note

Directory buckets - For directory buckets, you must make requests for this API operation to the Zonal endpoint. These endpoints support virtual-hosted-style requests in the format ``https://bucket_name.s3express-az_id.region.amazonaws.com/key-name ``. Path-style requests are not supported. For more information, see Regional and Zonal endpoints in the Amazon S3 User Guide.

Permissions

General purpose bucket permissions - To use GetObjectAttributes, you must have READ access to the object. The permissions that you need to use this operation with depend on whether the bucket is versioned. If the bucket is versioned, you need both the s3:GetObjectVersion and s3:GetObjectVersionAttributes permissions for this operation. If the bucket is not versioned, you need the s3:GetObject and s3:GetObjectAttributes permissions. For more information, see Specifying Permissions in a Policy in the Amazon S3 User Guide. If the object that you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.
- If you have the s3:ListBucket permission on the bucket, Amazon S3 returns an HTTP status code 404 Not Found (“no such key”) error.
- If you don’t have the s3:ListBucket permission, Amazon S3 returns an HTTP status code 403 Forbidden (“access denied”) error.
Directory bucket permissions - To grant access to this API operation on a directory bucket, we recommend that you use the CreateSession API operation for session-based authorization. Specifically, you grant the s3express:CreateSession permission to the directory bucket in a bucket policy or an IAM identity-based policy. Then, you make the CreateSession API call on the bucket to obtain a session token. With the session token in your request header, you can make API requests to this operation. After the session token expires, you make another CreateSession API call to generate a new session token for use. Amazon Web Services CLI or SDKs create session and refresh the session token automatically to avoid service interruptions when a session expires. For more information about authorization, see CreateSession.

Encryption

Note

Encryption request headers, like x-amz-server-side-encryption, should not be sent for HEAD requests if your object uses server-side encryption with Key Management Service (KMS) keys (SSE-KMS), dual-layer server-side encryption with Amazon Web Services KMS keys (DSSE-KMS), or server-side encryption with Amazon S3 managed encryption keys (SSE-S3). The x-amz-server-side-encryption header is used when you PUT an object to S3 and want to specify the encryption method. If you include this header in a GET request for an object that uses these types of keys, you’ll get an HTTP 400 Bad Request error. It’s because the encryption method can’t be changed when you retrieve the object.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you retrieve the metadata from the object, you must use the following headers to provide the encryption key for the server to be able to retrieve the object’s metadata. The headers are:

x-amz-server-side-encryption-customer-algorithm
x-amz-server-side-encryption-customer-key
x-amz-server-side-encryption-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.

Note

Directory bucket permissions - For directory buckets, only server-side encryption with Amazon S3 managed keys (SSE-S3) ( AES256) is supported.

Versioning

Directory buckets - S3 Versioning isn’t enabled and supported for directory buckets. For this API operation, only the null value of the version ID is supported by directory buckets. You can only specify null to the versionId query parameter in the request.

Conditional request headers

Consider the following when using request headers:

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows, then Amazon S3 returns the HTTP status code 200 OK and the data requested:
- If-Match condition evaluates to true.
- If-Unmodified-Since condition evaluates to false.

For more information about conditional requests, see RFC 7232.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows, then Amazon S3 returns the HTTP status code 304 Not Modified:
- If-None-Match condition evaluates to false.
- If-Modified-Since condition evaluates to true.

For more information about conditional requests, see RFC 7232.

HTTP Host header syntax

Directory buckets - The HTTP Host header syntax is Bucket_name.s3express-az_id.region.amazonaws.com.

The following actions are related to GetObjectAttributes:

Request Syntax

response = client.get_object_attributes(
    Bucket='string',
    Key='string',
    VersionId='string',
    MaxParts=123,
    PartNumberMarker=123,
    SSECustomerAlgorithm='string',
    SSECustomerKey='string',
    RequestPayer='requester',
    ExpectedBucketOwner='string',
    ObjectAttributes=[
        'ETag'|'Checksum'|'ObjectParts'|'StorageClass'|'ObjectSize',
    ]
)

Parameters:

Bucket (string) –
[REQUIRED]

The name of the bucket that contains the object.

Directory buckets - When you use this operation with a directory bucket, you must use virtual-hosted-style requests in the format Bucket_name.s3express-az_id.region.amazonaws.com. Path-style requests are not supported. Directory bucket names must be unique in the chosen Availability Zone. Bucket names must follow the format bucket_base_name--az-id--x-s3 (for example, DOC-EXAMPLE-BUCKET--usw2-az1--x-s3). For information about bucket naming restrictions, see Directory bucket naming rules in the Amazon S3 User Guide.

Access points - When you use this action with an access point, you must provide the alias of the access point in place of the bucket name or specify the access point ARN. When using the access point ARN, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.*Region*.amazonaws.com. When using this action with an access point through the Amazon Web Services SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using access points in the Amazon S3 User Guide.

Note
Access points and Object Lambda access points are not supported by directory buckets.

S3 on Outposts - When you use this action with Amazon S3 on Outposts, you must direct requests to the S3 on Outposts hostname. The S3 on Outposts hostname takes the form AccessPointName-AccountId.outpostID.s3-outposts.Region.amazonaws.com. When you use this action with S3 on Outposts through the Amazon Web Services SDKs, you provide the Outposts access point ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see What is S3 on Outposts? in the Amazon S3 User Guide.
Key (string) –
[REQUIRED]

The object key.
VersionId (string) –
The version ID used to reference a specific version of the object.

Note
S3 Versioning isn’t enabled and supported for directory buckets. For this API operation, only the null value of the version ID is supported by directory buckets. You can only specify null to the versionId query parameter in the request.
MaxParts (integer) – Sets the maximum number of parts to return.
PartNumberMarker (integer) – Specifies the part after which listing should begin. Only parts with higher part numbers will be listed.
SSECustomerAlgorithm (string) –
Specifies the algorithm to use when encrypting the object (for example, AES256).

Note
This functionality is not supported for directory buckets.
SSECustomerKey (string) –
Specifies the customer-provided encryption key for Amazon S3 to use in encrypting data. This value is used to store the object and then it is discarded; Amazon S3 does not store the encryption key. The key must be appropriate for use with the algorithm specified in the x-amz-server-side-encryption-customer-algorithm header.

Note
This functionality is not supported for directory buckets.
SSECustomerKeyMD5 (string) –
Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321. Amazon S3 uses this header for a message integrity check to ensure that the encryption key was transmitted without error.

Note
This functionality is not supported for directory buckets.

Please note that this parameter is automatically populated if it is not provided. Including this parameter is not required
RequestPayer (string) –
Confirms that the requester knows that they will be charged for the request. Bucket owners need not specify this parameter in their requests. If either the source or destination S3 bucket has Requester Pays enabled, the requester will pay for corresponding charges to copy the object. For information about downloading objects from Requester Pays buckets, see Downloading Objects in Requester Pays Buckets in the Amazon S3 User Guide.

Note
This functionality is not supported for directory buckets.
ExpectedBucketOwner (string) – The account ID of the expected bucket owner. If the account ID that you provide does not match the actual owner of the bucket, the request fails with the HTTP status code 403 Forbidden (access denied).
ObjectAttributes (list) –
[REQUIRED]

Specifies the fields at the root level that you want returned in the response. Fields that you do not specify are not returned.
- (string) –

Return type:

dict

Returns:

Response Syntax

{
    'DeleteMarker': True|False,
    'LastModified': datetime(2015, 1, 1),
    'VersionId': 'string',
    'RequestCharged': 'requester',
    'ETag': 'string',
    'Checksum': {
        'ChecksumCRC32': 'string',
        'ChecksumCRC32C': 'string',
        'ChecksumSHA1': 'string',
        'ChecksumSHA256': 'string'
    },
    'ObjectParts': {
        'TotalPartsCount': 123,
        'PartNumberMarker': 123,
        'NextPartNumberMarker': 123,
        'MaxParts': 123,
        'IsTruncated': True|False,
        'Parts': [
            {
                'PartNumber': 123,
                'Size': 123,
                'ChecksumCRC32': 'string',
                'ChecksumCRC32C': 'string',
                'ChecksumSHA1': 'string',
                'ChecksumSHA256': 'string'
            },
        ]
    },
    'StorageClass': 'STANDARD'|'REDUCED_REDUNDANCY'|'STANDARD_IA'|'ONEZONE_IA'|'INTELLIGENT_TIERING'|'GLACIER'|'DEEP_ARCHIVE'|'OUTPOSTS'|'GLACIER_IR'|'SNOW'|'EXPRESS_ONEZONE',
    'ObjectSize': 123
}

Response Structure

(dict) –
- DeleteMarker (boolean) –
  
  Specifies whether the object retrieved was ( true) or was not ( false) a delete marker. If false, this response header does not appear in the response.
  
  Note
  This functionality is not supported for directory buckets.
- LastModified (datetime) –
  
  The creation date of the object.
- VersionId (string) –
  
  The version ID of the object.
  
  Note
  This functionality is not supported for directory buckets.
- RequestCharged (string) –
  
  If present, indicates that the requester was successfully charged for the request.
  
  Note
  This functionality is not supported for directory buckets.
- ETag (string) –
  
  An ETag is an opaque identifier assigned by a web server to a specific version of a resource found at a URL.
- Checksum (dict) –
  
  The checksum or digest of the object.
  - ChecksumCRC32 (string) –
    
    The base64-encoded, 32-bit CRC32 checksum of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
  - ChecksumCRC32C (string) –
    
    The base64-encoded, 32-bit CRC32C checksum of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
  - ChecksumSHA1 (string) –
    
    The base64-encoded, 160-bit SHA-1 digest of the object. This will only be present if it was uploaded with the object. When you use the API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
  - ChecksumSHA256 (string) –
    
    The base64-encoded, 256-bit SHA-256 digest of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
- ObjectParts (dict) –
  
  A collection of parts associated with a multipart upload.
  - TotalPartsCount (integer) –
    
    The total number of parts.
  - PartNumberMarker (integer) –
    
    The marker for the current part.
  - NextPartNumberMarker (integer) –
    
    When a list is truncated, this element specifies the last part in the list, as well as the value to use for the PartNumberMarker request parameter in a subsequent request.
  - MaxParts (integer) –
    
    The maximum number of parts allowed in the response.
  - IsTruncated (boolean) –
    
    Indicates whether the returned list of parts is truncated. A value of true indicates that the list was truncated. A list can be truncated if the number of parts exceeds the limit returned in the MaxParts element.
  - Parts (list) –
    
    A container for elements related to a particular part. A response can contain zero or more Parts elements.
    Note
    - General purpose buckets - For GetObjectAttributes, if a additional checksum (including x-amz-checksum-crc32, x-amz-checksum-crc32c, x-amz-checksum-sha1, or x-amz-checksum-sha256) isn’t applied to the object specified in the request, the response doesn’t return Part.
    - Directory buckets - For GetObjectAttributes, no matter whether a additional checksum is applied to the object specified in the request, the response returns Part.
    - (dict) –
      
      A container for elements related to an individual part.
      - PartNumber (integer) –
        
        The part number identifying the part. This value is a positive integer between 1 and 10,000.
      - Size (integer) –
        
        The size of the uploaded part in bytes.
      - ChecksumCRC32 (string) –
        
        This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the base64-encoded, 32-bit CRC32 checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.
      - ChecksumCRC32C (string) –
        
        The base64-encoded, 32-bit CRC32C checksum of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
      - ChecksumSHA1 (string) –
        
        The base64-encoded, 160-bit SHA-1 digest of the object. This will only be present if it was uploaded with the object. When you use the API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
      - ChecksumSHA256 (string) –
        
        The base64-encoded, 256-bit SHA-256 digest of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it’s a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
- StorageClass (string) –
  
  Provides the storage class information of the object. Amazon S3 returns this header for all objects except for S3 Standard storage class objects.
  
  For more information, see Storage Classes.
  
  Note
  Directory buckets - Only the S3 Express One Zone storage class is supported by directory buckets to store objects.
- ObjectSize (integer) –
  
  The size of the object in bytes.

Exceptions

S3.Client.exceptions.NoSuchKey