HeadBucket
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 thex-amz-
prefix, includingx-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 theCreateSession
API operation.AWS 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 AWS 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-zone-id.region-code.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-zone-id.region-code.amazonaws.com
. Path-style requests are not supported. For more information about endpoints in Availability Zones, see Regional and Zonal endpoints for directory buckets in Availability Zones in the Amazon S3 User Guide. For more information about endpoints in Local Zones, see Available Local Zone for directory buckets in the Amazon S3 User Guide.
Request Syntax
HEAD / HTTP/1.1
Host: Bucket
.s3.amazonaws.com
x-amz-expected-bucket-owner: ExpectedBucketOwner
URI Request Parameters
The request uses the following URI parameters.
- Bucket
-
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-zone-id.region-code.amazonaws.com
. Path-style requests are not supported. Directory bucket names must be unique in the chosen Zone (Availability Zone or Local Zone). Bucket names must follow the formatbucket-base-name--zone-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 AWS 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 AWS 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.Required: Yes
- x-amz-expected-bucket-owner
-
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).
Request Body
The request does not have a request body.
Response Syntax
HTTP/1.1 200
x-amz-bucket-location-type: BucketLocationType
x-amz-bucket-location-name: BucketLocationName
x-amz-bucket-region: BucketRegion
x-amz-access-point-alias: AccessPointAlias
Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The response returns the following HTTP headers.
- x-amz-access-point-alias
-
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
. - x-amz-bucket-location-name
-
The name of the location where the bucket will be created.
For directory buckets, the Zone ID of the Availability Zone or the Local Zone where the bucket is created. An example Zone ID value for an Availability Zone is
usw2-az1
.Note
This functionality is only supported by directory buckets.
- x-amz-bucket-location-type
-
The type of location where the bucket is created.
Note
This functionality is only supported by directory buckets.
Valid Values:
AvailabilityZone | LocalZone
- x-amz-bucket-region
-
The Region that the bucket is located.
Length Constraints: Minimum length of 0. Maximum length of 20.
Errors
- NoSuchBucket
-
The specified bucket does not exist.
HTTP Status Code: 404
Examples
Sample Request for general purpose buckets
This example illustrates one usage of HeadBucket.
HEAD / HTTP/1.1 Date: Fri, 10 Feb 2012 21:34:55 GMT Authorization: authorization string Host: myawsbucket.s3.amazonaws.com Connection: Keep-Alive
Sample Response for general purpose buckets
This example illustrates one usage of HeadBucket.
HTTP/1.1 200 OK x-amz-id-2: JuKZqmXuiwFeDQxhD7M8KtsKobSzWA1QEjLbTMTagkKdBX2z7Il/jGhDeJ3j6s80 x-amz-request-id: 32FE2CEB32F5EE25 x-amz-bucket-region: us-west-2 x-amz-access-point-alias: false Date: Fri, 10 2012 21:34:56 GMT Server: AmazonS3
See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following: