Today, a variety of advanced Internet-of-Things applications like data collection apps for ambient assisted living services supporting elder patients or for the surveillance of smart homes are developed everywhere. Regarding such application scenarios and the requirement to securely disseminate the collected data, we present a fog computing architecture that integrates blockchain technology for privacy aware data sharing. The latter fog-blockchain prototype is based on a private, permissioned blockchain paradigm. We discuss a lightweight implementation of our proposed integrated fog node architecture using Hyperledger Fabric as blockchain with a peer-to-peer network among cheap single-board-computers as basic data collecting peers. Furthermore, we investigate the computing and network performance indices of our prototypical lightweight fog computing architecture.