Computing the cloud resources are complex in rich environments [2]. By enabling large-scale integration of building blocks, the development and deployment of Web applications is simplified. The cloud ecosystem is the composition of services, vendors, end users and technologies, and also their interactions and interfaces [3], [4]. However, the growing diversity of these elements poses as a significant challenge in order to build portable and adaptable applications. Subsections II-A and II-B provide two complementary concepts for organizing this ecosystem. The first one is based on cloud deployment models. The second is based on the distinction between inside and outside cloud.