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 generic400 Bad Request
,403 Forbidden
or404 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 thex-amz-
prefix, includingx-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 theCreateSession
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 theAction
element of a policy. By default, the session is in theReadWrite
mode. If you want to restrict the access, you can explicitly set thes3express:SessionMode
condition key toReadOnly
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.
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 formatbucket_base_name--az-id--x-s3
(for example,DOC-EXAMPLE-BUCKET--usw2-az2--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 aboutInvalidAccessPointAliasError
, 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-az2
.Note
This functionality is only supported by directory buckets.
BucketRegion (string) –
The Region that the bucket is located.
Note
This functionality is not supported for directory buckets.
AccessPointAlias (boolean) –
Indicates whether the bucket name used in the request is an access point alias.
Note
This functionality is not supported for directory buckets.
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': { '...': '...', }, }