Management Clusters
The management cluster runs Butler platform components and hosts tenant control planes. It is the foundation of a Butler deployment.
What Runs on It
| Component | Purpose |
|---|---|
| butler-controller | Reconciles TenantCluster, Team, ProviderConfig, and other Butler CRDs |
| butler-bootstrap | Orchestrates management cluster creation during initial setup |
| butler-server | HTTP/WebSocket API backend for the Console and CLI |
| butler-console | Web UI for cluster management |
| Steward | Runs tenant API servers, controller-managers, and schedulers as pods |
| Cluster API | Manages tenant worker VM lifecycle through infrastructure providers |
| Cilium | CNI for management cluster networking |
| Longhorn | Persistent storage for etcd and platform state |
| cert-manager | TLS certificate automation |
Topology Options
Butler supports two management cluster topologies:
HA (3 control plane nodes) -- Production deployments. Three control plane nodes with etcd distributed across them. kube-vip provides a virtual IP for API server high availability.
Single-node -- Development and evaluation. One node runs all control plane and worker components. Lower resource requirements, no HA.
Both topologies use Talos Linux as the node operating system. Talos provides an immutable, API-managed OS with no SSH access and a minimal attack surface.
Capacity
The practical capacity of a management cluster depends on etcd capacity, node resources, and the resource footprint of each tenant control plane. See the scaling guide for tuning guidance.
See Also
- Getting Started -- Bootstrap a management cluster
- Architecture -- Internal component interactions
- ButlerConfig Reference -- Platform-wide configuration