OpenStack – an API

One of the initial goals of OpenStack was to provide Application Program Interface (API) compatibility with the Amazon Web Service. As the popularity of the platform has increased, the OpenStack API has become a de facto standard on its own. In the November 2017 User Survey, the standard APIs were listed as the number one business driver for the adoption of OpenStack as a private cloud platform. As such, many of the enterprise organizations that we've worked with to create OpenStack clouds are using them as an underlying Infrastructure as a Service (IaaS) layer for one or more Platform as a Service (PaaS) or Hybrid Cloud deployments.

Every feature or function of OpenStack is exposed in one of its REST APIs. There are command-line interfaces for OpenStack (legacy nova and the newer openstack common client) as well as a standard web interface (Horizon). However, most interactions between the components and end users happen over the API. This is advantageous for the following reasons:

• Everything in the system can be automated
• Integration with other systems is well-defined
• Use cases can be clearly defined and automatically tested

The APIs are well-defined and versioned REST APIs, and there are native clients and SDKs for more than a dozen programming languages. For a full list of current SDKs, refer to: http://api.openstack.org.