KubeFlex

A flexible and scalable platform for running Kubernetes control plane APIs with multi-tenancy support.

KubeFlex is a CNCF sandbox project under the KubeStellar umbrella that enables “control-plane-as-a-service” multi-tenancy for Kubernetes.

Overview

KubeFlex provides a new approach to multi-tenancy by offering each tenant their own dedicated Kubernetes control plane and data-plane nodes in a cost-effective manner. It addresses the fundamental challenge of Kubernetes multi-tenancy by providing strong isolation at both control and data plane levels while maintaining cost efficiency through shared infrastructure.

Key Features

Feature	Description
Lightweight API Servers	Dedicated Kubernetes API servers with minimal resource footprint (~350MB)
Flexible Storage	Choose from shared Postgres, dedicated etcd, or Kine+Postgres configurations
Multiple Control Plane Types	Support for k8s, vcluster, host, ocm, and external cluster types
Unified CLI (kflex)	Single binary for initializing, managing, and switching between control planes
Zero-Touch Provisioning	Automated control plane creation and configuration

Architecture

KubeFlex implements a sophisticated multi-tenant architecture that separates control plane management from workload execution:

Core Components

KubeFlex Controller: Orchestrates the lifecycle of tenant control planes through the ControlPlane CRD
Tenant Control Planes: Isolated API server and controller manager instances per tenant
Flexible Data Plane: Choose between shared host nodes, vCluster virtual nodes, or dedicated KubeVirt VMs
Unified CLI (kflex): Single binary for initializing, managing, and switching between control planes
Storage Abstraction: Configurable backends from shared Postgres to dedicated etcd

Supported Control Plane Types

Type	Description
k8s	Lightweight Kubernetes API server (~350MB) with essential controllers, using shared Postgres via Kine
vcluster	Full virtual clusters based on the vCluster project, sharing host cluster worker nodes
host	The hosting cluster itself exposed as a control plane for management scenarios
ocm	Open Cluster Management control plane for multi-cluster federation scenarios
external	Import existing external clusters under KubeFlex management (roadmap)

For detailed architecture information, see the Architecture Guide.

Installation

kind and kubectl are required. A kind hosting cluster is created automatically by the kubeflex CLI. You may also install KubeFlex on other Kube distros, as long as they support an nginx ingress with SSL passthru, or on OpenShift. See the User’s Guide for more details.

Using the install script

sudo su <<EOF
bash <(curl -s https://raw.githubusercontent.com/kubestellar/kubeflex/main/scripts/install-kubeflex.sh) --ensure-folder /usr/local/bin --strip-bin
EOF

Using Homebrew

brew tap kubestellar/kubeflex https://github.com/kubestellar/kubeflex
brew install kflex

To upgrade:

brew upgrade kflex

Quick Start

Get started with KubeFlex quickly by following our Quick Start Guide. The guide includes:

Basic multi-tenant setup with step-by-step commands
Advanced development team scenarios with complete isolation
Context switching and control plane management
Cleanup and best practices

Documentation

Quick Start Guide: Get up and running quickly with KubeFlex
User Guide: Detailed usage instructions and advanced scenarios
Architecture Guide: Deep-dive into technical architecture
Multi-Tenancy Guide: Comprehensive multi-tenancy analysis and use cases

Community and Support

Issues and Features: GitHub Issues
Community Discussion: KubeStellar Slack
Source Code: GitHub Repository

License

KubeFlex is licensed under the Apache 2.0 License.

KubeFlex is part of the KubeStellar project, a CNCF sandbox initiative focused on multi-cluster configuration management for edge, multi-cloud, and hybrid cloud environments.