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.

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 error codes.

Note

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

Authentication and authorization

All 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 bucket - 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

• General purpose bucket permissions - To use this operation, you must have permissions to perform the s3:ListBucket action. The bucket owner has this permission by default and can grant this permission to others. For more information about permissions, see Managing access permissions to your Amazon S3 resources in the Amazon S3 User Guide.

• Directory bucket permissions - You must have the s3express:CreateSession permission in the Action element of a policy. By default, the session is in the ReadWrite mode. If you want to restrict the access, you can explicitly set the s3express:SessionMode condition key to ReadOnly on the bucket. For more information about example bucket policies, see Example bucket policies for S3 Express One Zone and Amazon Web Services Identity and Access Management (IAM) identity-based policies for S3 Express One Zone in the Amazon S3 User Guide.

  HTTP Host header syntax

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

See also: AWS API Documentation

Request Syntax

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

Parameters:

• Bucket (string) –

  [REQUIRED]

  The bucket name.

  When using this action with an access point, 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.

  When using 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 using this action with S3 on Outposts through the Amazon Web Services SDKs, you provide the Outposts bucket ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see Using Amazon S3 on Outposts in the Amazon S3 User Guide.

• ExpectedBucketOwner (string) – Ignored by COS if present.

Return type:

dict

Returns:

Response Syntax

{
    'IBMSSEKPEnabled': True|False,
    'IBMSSEKPCrkId': 'string'
}

Response Structure

• (dict) –

  • IBMSSEKPEnabled (boolean) – The bucket encryption enabled or not.

  • IBMSSEKPCrkId (string) – CRK ID of the Bucket encryption

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