HEAD Bucket

After being granted READ permission for a bucket, you can use this operation to query whether the bucket exists.

Request Syntax

HEAD / HTTP/1.1
 User-Agent: agent
 Host: bucketname.obs.example.com
 Accept: */*
 Date: date
 Authorization: authorization

Request Parameters

This request involves no parameters.

Request Headers

This request uses common headers. For details about common request headers, see section Common Request Headers.

If you want to obtain CORS configuration information, you must use the headers in Table 1.

Table 1 Request headers of CORS configuration

Header

Description

Remarks

Origin

Indicates an origin specified by a pre-request. Generally, it is a domain name.

Type: String

Mandatory

Access-Control-Request-Headers

Indicates the HTTP headers of a request. The request can use multiple HTTP headers.

Type: String

Optional

x-amz-security-token

Header field used to identify the request of a federated user. When the federal authentication function is enabled, users sending such requests are identified as federated users.

Type: string

Optional. This parameter must be carried in the request sent by federated users.

Request Elements

This request involves no elements.

Response Syntax

HTTP/1.1 status_code
 Server: Server Name
 x-amz-request-id: request id
 x-reserved: amazon, aws and amazon web services are trademarks or registered trademarks of Amazon Technologies, Inc
 x-amz-bucket-region: region name
 Content-Type: */*
 x-obs-version: version
 x-default-storage-class: staorage class
 x-amz-id-2: id
 Date: date
 Content-Length: length

Response Headers

This response uses common headers. For details about common response headers, see section Common Response Headers.

In addition to common headers, when CORS is configured for buckets, you can use the response headers in Table 2.

Table 2 Appended response headers when CORS is configured for buckets

Header

Description

Access-Control-Allow-Origin

If Origin in the request meets the CORS configuration requirements, Origin is included in the response.

Type: String

Access-Control-Allow-Headers

If headers in the request meet the CORS configuration requirements, headers are included in the response.

Type: String

Access-Control-Max-Age

Indicates MaxAgeSeconds in the CORS configuration of a server.

Type: Integer

Access-Control-Allow-Methods

If Access-Control-Request-Method in the request meets the CORS configuration requirements, methods in the rule are included in the response.

Type: String

Valid values: GET, PUT, HEAD, POST, and DELETE

Access-Control-Expose-Headers

Indicates ExposeHeader in the CORS configuration of a server.

Type: String

x-amz-bucket-region

Indicates the region of the bucket.

Type: String

Response Elements

This response involves no elements.

Error Responses

No special error responses are returned. For details about error responses, see Table 1.

Sample Request

HEAD / HTTP/1.1
 User-Agent: Jakarta Commons-HttpClient/3.1
 Host: bucketname.obs.example.com
 Accept: */*
 Date: Sun, 26 Sep 2010 09:16:00 GMT
 Authorization: AWS 04RZT432N80TGDF2Y2G2:JUtd9kkJFjbKbkP9f6T/tAxozYY=

Sample Response

HTTP/1.1 200 OK
Server: OBS
x-amz-request-id: 367CB63A2F283044981285492719060
x-reserved: amazon, aws and amazon web services are trademarks or registered trademarks of Amazon Technologies, Inc
x-amz-bucket-region: R1
Content-Type: application/xml
x-obs-version: 3.0

x-amz-id-2: MzY3Q0I2M0EyRjI4MzA0NDk4MTI4NTQ5MjcxOTA2MEFBQUFBQUFBYmJiYmJiYmJD
Date: Sun, 26 Sep 2010 09:18:36 GMT
Content-Length: 0

Sample Request (Getting Bucket Metadata and CORS Configuration when CORS is properly configured)

HEAD / HTTP/1.1
User-Agent: curl/7.19.0 (x86_64-suse-linux-gnu) libcurl/7.19.0 OpenSSL/0.9.8{ zlib/1.2.3 libidn/1.10
Host: bucketname.obs.example.com
Accept: */*
Date: Tue, 28 Apr 2015 13:47:30 +0000
Authorization: AWS D13E0C94E722DD69423C:1UL75oi0bFRpJlgZMfvh4lUyjBs=
Origin:www.example.com
Access-Control-Request-Headers:AllowedHeader_1

Sample Response (Getting Bucket Metadata and CORS Configuration when CORS is properly configured)

HTTP/1.1 200 OK
x-amz-request-id: BC4C45F57B0DED38D006D5F8FEB738C4
x-reserved: amazon, aws and amazon web services are trademarks or registered trademarks of Amazon Technologies, Inc
Access-Control-Allow-Origin: www.example.com
Access-Control-Allow-Methods: POST,GET,HEAD,PUT
Access-Control-Allow-Headers: AllowedHeader_1
Access-Control-Max-Age: 100
Access-Control-Expose-Headers: ExposeHeader_1
x-amz-bucket-region: R1
Content-Type: text/xml
x-obs-version: 3.0
x-default-storage-class: STANDARD
x-amz-id-2: YkFlH3FTA2Tf/lIc2XiyuICp/EUqpVI4j1/g5hlatg75TTZdERSCYliqitChspgA
Date: Tue, 28 Apr 2015 13:47:30 GMT
Content-Length: 0