The development and maintenance of cloud software is complicated by complex but crucial technological requirements that are tightly coupled with each other and with the softwares actual business functionality. Consequently, the complexity of design, implementation, deployment, and maintenance activities increases. We present an architecture description language that raises the level of technological abstraction by modeling cloud software as interactive systems. We show how its models correspond to an architecture style that particularly meets the requirements of cloud-based cyber-physical systems. The result provides a basis for an architecture-driven model-based methodology for engineering cloud software.