Kubernetes Cluster Federation (KubeFed for short) allows you to coordinate the configuration of multiple Kubernetes clusters from a single set of APIs in a hosting cluster. KubeFed aims to provide mechanisms for expressing which clusters should have their configuration managed and what that configuration should be. The mechanisms that KubeFed provides are intentionally low-level, and intended to be foundational for more complex multicluster use cases such as deploying multi-geo applications and disaster recovery.
KubeFed is currently alpha and moving rapidly toward its initial beta release.
KubeFed is configured with two types of information:
- Type configuration declares which API types KubeFed should handle
- Cluster configuration declares which clusters KubeFed should target
Propagation refers to the mechanism that distributes resources to federated clusters.
Type configuration has three fundamental concepts:
- Templates define the representation of a resource common across clusters
- Placement defines which clusters the resource is intended to appear in
- Overrides define per-cluster field-level variation to apply to the template
These three abstractions provide a concise representation of a resource intended to appear in multiple clusters. They encode the minimum information required for propagation and are well-suited to serve as the glue between any given propagation mechanism and higher-order behaviors like policy-based placement and dynamic scheduling.
These fundamental concepts provide building blocks that can be used by higher-level APIs:
- Status collects the status of resources distributed by KubeFed across all federated clusters
- Policy determines which subset of clusters a resource is allowed to be distributed to
- Scheduling refers to a decision-making capability that can decide how workloads should be spread across different clusters similar to how a human operator would
| Feature | Maturity | Feature Gate | Default |
|---|---|---|---|
| Push propagation of arbitrary types to remote clusters | Alpha | PushReconciler | true |
CLI utility (kubefedctl) |
Alpha | ||
| Generate KubeFed APIs without writing code | Alpha | ||
Multicluster Service DNS via external-dns |
Alpha | CrossClusterServiceDiscovery | true |
Multicluster Ingress DNS via external-dns |
Alpha | FederatedIngress | true |
| Replica Scheduling Preferences | Alpha | SchedulerPreferences | true |
Take a look at our user guide if you are interested in using KubeFed.
Take a look at our development guide if you are interested in contributing.
Participation in the Kubernetes community is governed by the Kubernetes Code of Conduct.