Cluster Federation in Kubernetes 1.5: Managing Multi-Cluster Deployments

Introduction

Kubernetes 1.5 introduces Cluster Federation (Federation v1) to coordinate multiple clusters from a single control plane, aiming for higher availability and global placement.

Capabilities

• Federated Services & Ingress for cross‑cluster discovery.
• Federated Deployments to spread replicas across regions.
• Single Pane of Control to apply policies consistently.
• Federated ConfigMaps & Secrets (Alpha) unlock centralized configuration distribution with namespace scoping.
• kubefed join triangles make onboarding clusters simpler with generated credentials and DNS records.

Early Caveats

• Feature coverage is selective; not all resource types are federated yet.
• Operational tooling and failure testing are still early days.
• Controllers run with eventual consistency—expect short-lived skews between member clusters.
• Upgrades require careful choreography: update federation control plane, then member clusters, and finally re-run kubefed health checks.

Conclusion

Federation in 2016 is a promising start for multi‑cluster management, especially for multi‑region and hybrid setups.

• Before adopting, compare against simpler approaches like geo-aware DNS + manual replication; Federation shines once you need dozens of services coordinated across clouds.
• Keep a rollback plan: deleting federated objects can orphan resources in member clusters, so track them with labels for manual cleanup.