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ADR-008: Bare-Metal Management Plane

Status: Approved

Date: 2026-06-30

Decision

The 7KGroup management plane runs on a self-hosted Kubernetes cluster on bare-metal servers managed by 7KGroup, not on a public cloud provider for v1.

Rationale

  • Reduces cloud dependency for the operational hub
  • Provides predictable long-term infrastructure costs
  • Keeps sensitive fleet metadata and observability data under 7KGroup control
  • Aligns with current open decision OD-003

Scope of Concern

The bare-metal servers and underlying infrastructure (power, network, storage, HA, backups) are owned and operated by 7KGroup outside the scope of this architecture. From the perspective of 7k-inari, the management plane is treated as a Kubernetes cluster.

Architecture and runbooks in this repository focus on:

  • Kubernetes resources running in the management plane
  • Application-level backup and restore (etcd snapshots, PV backups, Git state)
  • Management-plane component configuration

Operational concerns such as server hardware, physical networking, RAID, redundant power, and datacenter availability are handled by the infrastructure team and are not documented here.

Trade-offs

  • 7KGroup is responsible for hardware, networking, and physical maintenance
  • Requires robust backup and disaster recovery planning at the Kubernetes layer
  • Slightly slower scaling than cloud-managed Kubernetes

Implementation Notes

  • The specific Kubernetes distribution (k3s, kubeadm, Talos, etc.) will be selected during Phase 1.
  • The management plane remains strictly fleet-only; see ADR-007.
  • DR strategy focuses on Kubernetes-level recovery (etcd, persistent volumes, GitOps state).