The Block Storage API supports both the JSON and XML data serialization formats. The
request format is specified using the Content-Type header and is required for
calls that have a request body. The response format can be specified in requests either by
using the Accept header or by adding an .xml or .json
extension to the request URI. Note that it is possible for a response to be serialized using
a format different from the request. If no response format is specified, JSON is the
default. If conflicting formats are specified using both an Accept header and a
query extension, the query extension takes precedence.
| Format | Accept Header | Query Extension | Default |
| JSON | application/json | .json | Yes |
| XML | application/xml | .xml | No |
In the request example below, notice that Content-Type is set to
application/json, but application/xml is
requested via the Accept header:
Example 1.1. Request with Headers (Getting Volume Types)
GET /v1/441446/types HTTP/1.1
Host: dfw.blockstorage.api.openstackcloud.com
X-Auth-Token: eaaafd18-0fed-4b3a-81b4-663c99ec1cbb
Accept: application/xml
Therefore an XML response format is returned:
Example 1.2. Response with Headers
HTTP/1.1 200 OK
Date: Fri, 20 Jul 2012 20:32:13 GMT
Content-Length: 187
Content-Type: application/xml
X-Compute-Request-Id: req-8e0295cd-a283-46e4-96da-cae05cbfd1c7
<?xml version='1.0' encoding='UTF-8'?>
<volume_types>
<volume_type id="1" name="SATA">
<extra_specs/>
</volume_type>
<volume_type id="2" name="SSD">
<extra_specs/>
</volume_type>
</volume_types>
