Optimizing the deployment of applications in Infrastructure-as-a-Service clouds requires to evaluate the costs and performance of different combinations of cloud configurations which is unfortunately a cumbersome and error-prone process. In this paper, we present Cloud WorkBench (CWB), a concrete implementation of a cloud benchmarking Web service, which fosters the definition of reusable and representative benchmarks. We demonstrate the complete cycle of benchmarking an IaaS service with the sample benchmark SysBench. In distinction to existing work, our system is based on the notion of Infrastructure-as-Code, which is a state of the art concept to define IT infrastructure in a reproducible, well-defined, and testable way.