The adoption level of an API make it a standard API in the industry. In this section, we go over Amazon EC2 interface and Open Virtualization Format (OVF) as the current standards in the real world of cloud computing. In addition, we introduce Venus-C project that supports Open Cloud Computing Interface (OCCI) and the Cloud Data Management Interface (CDMI) to have more discussion of standards use.
2.1 Amazon Interfaces
Amazon cloud interfaces are de facto standards in the cloud computing landscape. For instance, the EC2 API is a de facto standard in IaaS cloud while it was not designed as an industry-standard API. They have more impact than formal standards so far as everybody builds an EC2 interface to their IaaS.
The EC2 API was designed based on the needs of Amazon Web Services. Currently, many projects from Eucalyptus and OpenNebula to OpenStack to enStratus to AWS, implement and use the EC2 APIs. This is due to the suitability of the EC2 API as a de facto standard. Thus, at least in the cloud industry, Amazon is the leader to push their cloud APIs.
In detail, the EC2 API consists of a SOAP API and a query API. Leveraging the SOAP API is not very common among the AWS ecosystem, it is common among the in-house applications. The query API is further divided into query by POST and GET. Thus, infrastructure level operations can be performed by using SOAP, HTTP GET, and HTTP POST.
The problem with Amazon interfaces is that services have different authentication and request signing mechanisms. For example, EC2 has three different versions of authentication.
ElasticFox, boto, jclouds, lib cloud, and Dasein Cloud are all using slightly different variants of EC2 APIs. Some use the HTTP GET while some use the HTTP post. Some use one timestamp format, others use different ones, etc.