S3 / Client / head_bucket

head_bucket#

S3.Client.head_bucket(**kwargs)#

You can use this operation to determine if a bucket exists and if you have permission to access it. The action returns a 200 OK if the bucket exists and you have permission to access it.

Note

If the bucket does not exist or you do not have permission to access it, the HEAD request returns a generic 400 Bad Request, 403 Forbidden or 404 Not Found code. A message body is not included, so you cannot determine the exception beyond these HTTP response codes.

Authentication and authorization

General purpose buckets - Request to public buckets that grant the s3:ListBucket permission publicly do not need to be signed. All other HeadBucket requests must be authenticated and signed by using IAM credentials (access key ID and secret access key for the IAM identities). All headers with the x-amz- prefix, including x-amz-copy-source, must be signed. For more information, see REST Authentication.

Directory buckets - You must use IAM credentials to authenticate and authorize your access to the HeadBucket API operation, instead of using the temporary security credentials through the CreateSession API operation.

Amazon Web Services CLI or SDKs handles authentication and authorization on your behalf.

Permissions

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

Note

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. Path-style requests are not supported. For more information, see Regional and Zonal endpoints in the Amazon S3 User Guide.

See also: AWS API Documentation

Request Syntax

response = client.head_bucket(
    Bucket='string',
    ExpectedBucketOwner='string'
)
Parameters:

  • Bucket (string) –

    [REQUIRED]

    The bucket name.

    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.

    Object Lambda access points - When you use this API operation with an Object Lambda access point, provide the alias of the Object Lambda access point in place of the bucket name. If the Object Lambda access point alias in a request is not valid, the error code InvalidAccessPointAliasError is returned. For more information about InvalidAccessPointAliasError, see List of Error Codes.

    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.

  • 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).

Return type:

dict

Returns:

Response Syntax

{
    'BucketLocationType': 'AvailabilityZone',
    'BucketLocationName': 'string',
    'BucketRegion': 'string',
    'AccessPointAlias': True|False
}

Response Structure

  • (dict) –

    • BucketLocationType (string) –

      The type of location where the bucket is created.

      Note

      This functionality is only supported by directory buckets.

    • BucketLocationName (string) –

      The name of the location where the bucket will be created.

      For directory buckets, the AZ ID of the Availability Zone where the bucket is created. An example AZ ID value is usw2-az1.

      Note

      This functionality is only supported by directory buckets.

    • BucketRegion (string) –

      The Region that the bucket is located.

    • AccessPointAlias (boolean) –

      Indicates whether the bucket name used in the request is an access point alias.

      Note

      For directory buckets, the value of this field is false.

Exceptions

  • S3.Client.exceptions.NoSuchBucket

Examples

This operation checks to see if a bucket exists.

response = client.head_bucket(
    Bucket='acl1',
)

print(response)

Expected Output:

{
    'ResponseMetadata': {
        '...': '...',
    },
}