Nowadays, Fog computing is facing the requirements of time-sensitive applications in the IoT-cloud continuum. These requirements are decisive for mission-critical applications like structural health monitoring. In this paper, a portable Fog computing infrastructure, known as FogPi, is presented. This infrastructure has been designed around Raspberry Pi, which offers a low-cost and scalable solution for running containerized applications. FogPi allows the deployment, management, and orchestration of Docker containers and is especially suitable for environments where the limited Internet connection and reduced budgets limit the adoption of Fog and Edge deployments.