As a developer working in the cloud, you're probably aware that OpenStack (and the cloud industry in general) have moved away from supporting XML APIs. In fact, OpenStack has just eliminated XML support for the Compute v2 API in its latest "Kilo" release. In our quest at Rackspace to be as consistent as possible with upstream OpenStack, we are planning to follow suit. The last day of XML support in the Rackspace public cloud will be July 20, 2015.
But what about all the people who use XML?
There actually aren't very many. In the Rackspace public cloud, only 0.2% of current Next Generation Cloud Servers API requests either pass XML in the request body or request XML responses.
Remember, we're only talking about XML usage with the Next Generation Cloud Servers (Compute v2) API. You're perfectly free to use XML in any other context you like, for example, as a data interchange format for messages sent among your fleet of cloud servers. We're not making a moral judgement about XML usage, we're just saying that you'll no longer be able to pass it in a request body or ask for it as a response format when you communicate with the Rackspace Next Generation Cloud Servers API.
Dang! I'm using XML ... what can I do?
If you're using an SDK ...
If you are using a cloud software development kit (SDK), please update it. The latest version should be able to communicate with all OpenStack clouds using the supported JSON serialization format.
If you're using a custom script ...
If you are using a custom script without an SDK, you'll have to change your script to process JSON instead of XML. We strongly recommend, however, that you change your script to use one of the many available SDKs for various programming languages. The advantage to using an SDK is that it will expose a well-defined interface to your script, thereby making your script easier to maintain.
If you like to do it by hand ...
If you prefer to do things by hand, you'll need to modify your scripts
so that instead of sending XML, they'll send JSON request bodies. The
correct format for JSON requests can be found in the Compute API
Be sure that your scripts specify
in the request header.
You'll also need to change your scripts to parse JSON responses. Again,
the response format you can expect can be found in the Compute API
Make sure that your request either contains no
Accept" header, or that
it explicitly specifies
Accept: application/json in the request
How easy a transition this is depends upon what scripting language you are using. Some languages (Python, for example) handle JSON serialization and deserialization much more easily than others. If you need to do a major rewrite of your scripts, we strongly recommend considering using an SDK instead of a raw language ... it makes upgrades much easier on you.
Could I be using XML without knowing it?
I've spoken with a few customers who were making XML requests without knowing it. In some cases, this is because they were using an older version of an SDK that still used XML. The most recent versions of currently maintained OpenStack SDKs don't use XML, so an upgrade will fix this problem.
In conclusion, mark July 20, 2015 on your calendar as the last day of XML support for the Rackspace Cloud Servers API. If you have questions or comments about this transition, feel free to reach out to your Account Manager.