Lessons learned building a Raspberry Pi cluster

Amidst the COVID-19 pandemic, Shawn Sesna embarked on a project to create a Raspberry Pi cluster using Docker Swarm, driven by a desire to explore cluster computing and the new Raspberry Pi 4. The project aimed to shift some computing resources from a home hypervisor server to the energy-efficient Raspberry Pi cluster, while also deepening Sesna's understanding of Docker Swarm. The endeavor revealed several insights, such as the limited availability of ARM-compatible Docker images and the nuances of using Docker Swarm for service creation. Sesna also encountered challenges related to persistent storage, leading to the adoption of network storage solutions like CIFS for seamless container operations. Despite some troubleshooting, particularly with permissions and database compatibility issues, Sesna successfully configured a functioning system, including transitioning to a MySQL database to overcome SqlLite limitations. Overall, the project provided a platform for learning about Docker Swarm and Kubernetes, highlighting both the capabilities and constraints of running applications on a Raspberry Pi cluster.