tenantplane

Introduction

What tenantplane is, who it's for, and the principles behind it.

tenantplane is a lightweight, inspectable control plane for managing virtual Kubernetes tenants. It gives platform engineering teams multi-tenancy where synchronization, isolation, and day-2 operations stay predictable and explainable.

The problem

As Kubernetes adoption grows, platform teams need to hand out cluster-like environments to many teams, CI pipelines, and preview deployments — without running a full cluster for each one. Existing virtual-cluster approaches work, but they often become hard to operate: the host view and the tenant view drift, isolation is implicit, and nobody can answer why a particular host object exists.

The approach

tenantplane treats the two hardest parts of multi-tenancy — synchronization and isolation — as first-class, visible subsystems.

  • Each tenant runs a small k3s control plane inside a host namespace, provisioned and reconciled by the tenantplane controller.
  • A SyncPolicy declares which resources cross the virtual-to-host boundary. The sync engine maps every tenant object to a deterministic host object and records a decision for each action.
  • An IsolationProfile composes NetworkPolicy, ResourceQuota, LimitRange, and Pod Security into one explicit boundary.

Who it’s for

  • Platform teams building internal developer platforms.
  • CI/CD and preview-environment systems that need high-density, ephemeral tenant clusters.
  • Anyone who has to answer audit questions about what runs where and why.

Coming from vcluster, Kamaji, or Capsule and wondering how tenantplane differs? See Why tenantplane — it uses the per-tenant control-plane pattern as an implementation detail and builds a distinct, explainability-first product on top.

Design principles

  • Every synchronization decision should be explainable.
  • Every isolation boundary should be explicit.
  • Platform operations should remain transparent.
  • The host cluster should always remain understandable and observable.
  • Tenant environments should evolve as isolation requirements change.

Project status

tenantplane is in early development. Today the controller provisions a shared-mode control plane, applies isolation, extracts a tenant kubeconfig, and runs host-ward resource sync with decisions surfaced as Kubernetes Events. See the Roadmap for what’s next, and expect pre-1.0 APIs to change.

Found a gap? Open an issue or PR.