Sending an OPTIONS Request to a Bucket - OptionsBucket

Function

Browsers automatically send OPTIONS requests (preflight requests) before cross-origin calls to verify whether the clients have required permissions to perform operations on servers. Subsequent requests are executed only after preflight requests are successful.

OBS allows static web resources to be stored in buckets with appropriate configurations. In this scenario, buckets in the OBS serve as servers to process OPTIONS preflight requests from clients.

Constraints

OBS can process OPTIONS preflight requests only after CORS is configured for desired buckets in OBS. Otherwise, a 403 Forbidden error will be returned for OPTIONS requests. For details about how to configure CORS, see Configuring CORS for a Bucket.

Differences Between OPTIONS Bucket and OPTIONS Object

With the OPTIONS Object, you need to specify an object name in the URL, but an object name is not required with the OPTIONS Bucket, which uses the bucket domain name as the URL. The request lines of the two methods are as follows:

OPTIONS /object HTTP/1.1

OPTIONS / HTTP/1.1

URI

OPTIONS /

Calling Method

For details, see Calling APIs. Before calling this API, calculate the API signature and add it to the request.

You can debug this API in API Explorer.

Request Syntax

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OPTIONS / HTTP/1.1 
Host: bucketname.obs.region.myhuaweicloud.com 
Date: date
Authorization: authorization
Origin: origin
Access-Control-Request-Method: method

URI Parameters

This request contains no URI parameters.

Request Headers

This request contains the headers described in Table 1.

Request Body

This request contains no request body parameters.

Response Syntax

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HTTP/1.1 status_code
Access-Control-Allow-Origin: origin
Access-Control-Allow-Methods: method
Access-Control-Allow-Headers: header
Access-Control-Max-Age: time
Access-Control-Expose-Headers: header
Access-Control-Allow-Credentials: credentials
Date: date
Content-Length: length

Response Headers

This response contains the headers described in Table 2.

Response Body

This response contains no elements.

Error Responses

Table 3 describes possible special errors in this request.

Refer to Error Code Overview for all other errors.

Sample Request

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OPTIONS / HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.myhuaweicloud.com
Accept: */*
Date: Wed, 01 Jul 2015 04:02:15 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:7RqP1vjemo6U+Adv9/Y6eGzWrzA=
Origin: www.example.com
Access-Control-Request-Method: PUT

Sample Response

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HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: BF260000016436314E8FF936946DBC9C
Access-Control-Allow-Origin: www.example.com
Access-Control-Allow-Methods: POST,GET,HEAD,PUT,DELETE
Access-Control-Max-Age: 100
Access-Control-Expose-Headers: ExposeHeader_1,ExposeHeader_2
Access-Control-Allow-Credentials: true
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCTlYimJvOyJncCLNm5y/iz6MAGLNxTuS
Date: Wed, 01 Jul 2015 04:02:15 GMT
Content-Length: 0

Helpful Links

• For more information about CORS, see Configuring CORS to Allow Cross-Origin Access to OBS.
• For details about the billing items involved in API operations, see Billing Items.