The document discusses setting up a Docker Swarm cluster with 3 Raspberry Pi nodes and integrating Consul for service discovery. It begins with an introduction to Consul and its key features like service discovery, health checking, and key-value storage. It then describes deploying Consul and a Swarm master on one node, registering a sample web service, and verifying the cluster. Finally, it explores the Consul UI and adds a Docker UI for visualizing the cluster.