The diversity in the way in which different cloud providers offer their services, give their SLAs, present their QoS, or support different technologies complicates the portability and interoperability of cloud applications, and favors vendor lock-in. Trying to solve these issues, we have recently witnessed the proposal of unified APIs for IaaS services, unified APIs for PaaS services, and a variety of cross-cloud application management tools. We go one step further in the unification of cloud services, building on the TOSCA and CAMP standards, with a proposal in which the management of IaaS and PaaS services, possibly offered by different providers, are integrated into a unified interface. The TOSCA standard is used for the definition of portable models describing the topology of cloud applications and the required resources in an agnostic, providers-and-resources-independent way. Based on the CAMP standard, we abstract from the particularities of specific providers. Indeed, to change the service on which any of the modules of an application is to be deployed, whether it be IaaS or PaaS, we just need to change its target location by picking from the catalog of supported locations. We provide insights into our implementation on Apache Brooklyn, present a non-trivial case study that illustrates our approach, and show some experimental results.
