Cluster federation is conceptually simple. You aggregate multiple Kubernetes clusters and treat them as a single logical cluster. There is a federation control plane that presents to clients a single unified view of the system.
The following diagram demonstrates the big picture of Kubernetes cluster federation:
The federation control plane consists of a federation API server and a federation controller manager that collaborate. The federated API server forwards requests to all the clusters in the federation. In addition, the federated controller manager performs the duties of the controller manager across all clusters by routing requests to the individual federation cluster members' changes. In practice, cluster federation is not trivial and can't be totally abstracted away. Cross-pod communication and data transfer may suddenly incur...
