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SUSE Rancher Prime 2.8.6, CLASTIX Kamaji 1.0.0

Efficient Multi-Tenancy with CLASTIX Kamaji and SUSE Rancher Prime

Centrally Orchestrate Isolated Kubernetes Control Planes

Technical Reference Documentation
Authors
Dario Tranchitella, CTO (CLASTIX)
Dominic Geeverghese, Solution Architect, MSP Alliances (SUSE)
Terry Smith, Director, Global Alliances Solutions (SUSE)
Image
SUSE Rancher Prime 2.8.6
CLASTIX Kamaji 1.0.0
Date: 2024-09-29
Summary

Streamline deployment and management of multi-tenant Kubernetes landscapes with SUSE Rancher Prime and CLASTIX Kamaji.

Disclaimer

Documents published as part of the series SUSE Technical Reference Documentation have been contributed voluntarily by SUSE employees and third parties. They are meant to serve as examples of how particular actions can be performed. They have been compiled with utmost attention to detail. However, this does not guarantee complete accuracy. SUSE cannot verify that actions described in these documents do what is claimed or whether actions described have unintended consequences. SUSE LLC, its affiliates, the authors, and the translators may not be held liable for possible errors or the consequences thereof.

1 Introduction

Efficiency, security, and cost savings are top concerns for most businesses. This becomes particularly important for large enterprises, who need to share Kubernetes infrastructure and resources between multiple teams, departments, or business units. These are also concerns for managed services providers, who offer Kubernetes-as-a-Service or leverage Kubernetes to deliver other services.

Multi-tenancy enables different users or tenants to securely share Kubernetes resources, simplifying administration and reducing costs. Multi-tenancy is recognized as key to achieving these goals. Yet Kubernetes does not have first-class concepts of end users or tenants.

SUSE | CLASTIX

By integrating CLASTIX Kamaji into your SUSE Rancher Prime environment, you gain:

  • A highly scalable and high-density Kubernetes control plane infrastructure.

  • Reduced operational overhead, yielding faster deployment, configuration, upgrades, and maintenance.

  • Consistent configurations across multiple tenants.

  • Distributed architectures across clouds, edge, and data center.

  • Hard multi-tenancy with strong security and isolation.

1.1 Scope

Learn how to deploy CLASTIX Kamaji into an existing Kubernetes cluster managed by SUSE Rancher Prime.

1.2 Audience

Systems architects, platform engineers, administrators, and others seeking efficient operation of Kubernetes infrastructure through multi-tenancy and secure workload isolation will find this guide relevant.

A basic understanding of Kubernetes and cluster management with SUSE Rancher Prime is needed.

2 Prerequisites

For this guide, you need the following:

  • SUSE Rancher Prime

    You can follow this guide with SUSE Rancher 2.8.6 or later. See Rancher Deployment Quick Start Guides for setting up your Rancher environment.

  • A Kubernetes cluster to be the Kamaji Admin Cluster and managed by SUSE Rancher.

    Any CNCF-certified Kubernetes cluster can be used, including RKE2 and K3s. Follow the instructions of your chosen Kubernetes distribution for proper setup of the Kamaji Admin Cluster.

    For this guide, in addition to the cluster’s control plane nodes, you need at least 3 worker nodes. Each worker node should have the following minimum specifications:

    • 2 vCPUs

    • 2 GB of RAM

    • 16 GB storage

    • Swap disabled

    • Full network connectivity between all machines

    Your Kamaji Admin Cluster also must provide the following services:

    • A Container Storage Interface (CSI) module installed with a defined Storage Class for the tenant datastores. For example, you can use Rancher Longhorn or any other persistent storage system. The Rancher Local Path Provisioner is also an option.

    • Support for Load Balancer service types, such as MetalLB or one provided by your cloud provider. The addresses provided by the load balancer must be accessible by the worker nodes of the tenant clusters as well as by tenant users.

    • Ingress Controller. The Kamaji Console is exposed through Ingress, so the cluster needs an Ingress controller. For RKE2 and K3s installations, you an ingress controller is installed by default. For other Kubernetes distributions, such as AKS, EKS, or GKE, you may need to deploy the ingress controller before continuing.

    • Cert-Manager. Kamaji takes advantage of dynamic admission control, such as validating and mutating webhook configurations. These webhooks are secured by Transport Layer Security (TLS), and the certificates are managed by Cert-Manager.

  • An arbitrary number of Linux machines to host multiple tenant worker nodes. These can be bare metal systems or virtual machines, on-premises or in any cloud. For this guide, each tenant worker node should have at least:

    • 2 vCPUs

    • 2 GB of RAM

    • 16 GB of storage

    • Swap disabled

    • Full network connectivity between all machines

      Note
      Note

      Kubernetes components communicate through various network ports and protocols.

  • A Linux workstation with the following tools installed:

3 Technical overview

Kamaji + Rancher Prime Architecture

CLASTIX Kamaji turns any CNCF-compliant Kubernetes cluster into an “Admin Cluster” to orchestrate other Kubernetes clusters called “tenant clusters.” With Kamaji, the tenant control planes run in pods on the Admin Cluster instead of on dedicated machines. This makes running Kubernetes at scale less costly, easier to deploy, and simpler to operate while providing users with a fully managed, native Kubernetes experience.

After a tenant cluster is created, you can import it into SUSE Rancher Prime for centralized management of your Kubernetes landscape, empowering global administrators to streamline operations and improve consistency and security through an intuitive interface as well as GitOps-driven workflows.

3.1 Components and tools

Key Kamaji components discussed in this guide are:

Kamaji Operator

The Kamaji Operator is installed on the Admin Cluster. It is responsible for creating and monitoring multiple custom resources called tenant control planes (TCPs).

  • The Kamaji Operator continuously checks for any deviations or changes in the TCPs. If it detects any drift, such as misconfigurations or inconsistencies, it initiates immediate reconciliation to bring the TCPs back to their desired states.

  • The Kamaji Operator rolls out new versions of TCPs and seamlessly migrates between different datastores. It ensures smooth transitions and minimizes disruptions during updates or changes to the control plane infrastructure.

Kamaji Console

The Kamaji Console is a Web-based, graphical interface for global administrators.

Tenant Control Plane (TCP)

Running in the Admin Cluster as pods, tenant control planes provide dedicated control plane capabilities for each tenant cluster. They expose the control plane endpoint (the address and port) to the tenant’s worker nodes through a balanced and secure network service.

Datastore

Installed on the Admin Cluster, the datastore is responsible for storing the state of the tenant clusters into a multi-tenant capable datastore as etcd running on the Admin Cluster. The relationship between the datastore and TCPs can be one-to-one or one-to-many. Thanks to kine integration, an open source component from SUSE acting as a shim for etcd, Kamaji supports other datastore types, including PostgreSQL and MySQL.

Tip
Tip

It is highly recommended that you use a managed datastore in production, such as CloudNativePG, an open source, PostgreSQL distribution for Kubernetes. You can also use the {https://github.com/clastix/kamaji-etcd}[kamaji-etcd] Helm chart to set up a multi-tenant etcd datastore, running as a StatefulSet of three replicas.

Tenant Worker Nodes

Tenant worker nodes run workloads of the respective tenants. They consist of virtual or bare metal machines that are connected to the TCP through a secure network connection. Tenant worker nodes can be isolated by infrastructure for hard multi-tenancy and can run on different infrastructures in data centers, clouds, and edge locations.

Konnectivity

Konnectivity is a cloud-native network technology that facilitates traffic between the TCP and the worker nodes. It establishes a secure tunnel between the TCP and the tenant worker nodes, which is especially useful when the worker nodes are not directly reachable from the TCP.

You can find additional details in the Kamaji documentation.

3.2 Workflow

The workflow for this guide and in general for working with Kamaji in a SUSE Rancher landscape is as follows:

  1. Installing Kamaji

    1. Installing Kamaji Operator

    2. Installing Kamaji Console

    3. Verifying Kamaji Operator and Kamaji Console

    4. Installing Kamaji UI Extension for SUSE Rancher

  2. Provisioning a tenant cluster

    1. Deploying a tenant control plane

    2. Joining worker nodes

    3. Installing the Cluster Network Interface

  3. Importing the tenant cluster into SUSE Rancher

4 Installation

CLASTIX Kamaji is available for easy installation through the SUSE Rancher User Interface (UI). SUSE Rancher Apps is a curated collection of software, packaged and maintained as Helm charts to simplify installation. The Kamaji Operator and the Kamaji Console are both available as Rancher App charts.

In addition, CLASTIX has created a SUSE Rancher UI Extension. SUSE Rancher UI Extensions allow users, developers, partners, and customers to extend and enhance the SUSE Rancher UI.

4.1 Install the Kamaji Operator

Install the Kamaji Operator and default datastore with the SUSE Rancher Apps chart.

  1. Log in to the SUSE Rancher UI.

  2. Select the Kamaji Admin Cluster you provisioned as part of the prerequisites for this guide.

  3. Navigate to Apps > Charts and search for 'kamaji'.

    Kamaji Rancher Charts
  4. Click the Kamaji chart to begin installation of the Kamaji Operator.

  5. In Namespace, select 'Create new namespace' and enter a name, such as 'kamaji-system'.

    Optionally select Customize Helm options before install to customize the deployment.

    Kamaji Rancher Chart - Namespace
  6. Click Next, then click Install.

4.2 Install the Kamaji Console

Install the Kamaji Console through the SUSE Rancher Apps chart.

  1. In the SUSE Rancher UI, select Apps > Charts and search for 'Kamaji Console'.

  2. Click the Kamaji Console chart to begin installation.

  3. Select 'kamaji-system' in Namespace, then click Next.

    Optionally, select Customize Helm options before install to customize the deployment.

    Kamaji Console Rancher Chart Installation Step 1
  4. Select Console Configuration and make the following adjustments:

    1. Enable the Generate Console Config Secret option.

    2. Fill in each of the required fields with appropriate values.

      Kamaji Console Rancher Chart Installation Step 2 - Console Configuration
  5. Select Ingress Configuration and make the following adjustments:

    1. Ensure Manage Ingress Status is enabled.

    2. Fill in each of the required fields with appropriate values.

      Kamaji Console Rancher Chart Installation Step 2 - Ingress Configuration
    3. Finish the installation by clicking Install.

4.3 Verify installation of Kamaji Operator and Kamaji Console

Verify that the Kamaji Operator and Kamaji Console are installed.

  1. In the SUSE Rancher UI, make sure you have selected the Kamaji Admin Cluster.

  2. Select Installed Apps.

  3. Verify that 'kamaji', 'console', and 'etcd' are listed.

    Installed Kamaji Apps

4.4 Install Kamaji UI Extension for SUSE Rancher

SUSE Rancher UI Extensions allow users, developers, partners, and customers to extend and enhance the SUSE Rancher UI. Examples of built-in Kamaji extensions are Fleet, Explorer, and Harvester. Other extensions that use the extensions API can be manually added.

  1. In the SUSE Rancher UI, select Extensions.

  2. Add the Partner Extensions repository.

    1. Click the three vertical dots in the upper right of the screen and select Manage Repositories > Create.

      Rancher Extensions page
    2. For Name, enter 'partner-extensions'.

    3. For Git Repo URL enter 'https://github.com/rancher/partner-extensions'.

    4. For Git Branch, enter 'main'.

    5. Click Create to add the Partner Extensions repository.

  3. Install the Kamaji Extension.

    1. Select the Available tab.

    2. Locate the Kamaji Extension and click Install.

    3. After installation completes, click Reload.

      Rancher Extensions - Reload
  4. Verify that the Kamaji Extension is installed.

    1. Note that the Kamaji Extension appears in the Installed tab of the Extensions page.

      Rancher Extensions - Kamaji installed
    2. With the Kamaji Extension installed, the SUSE Rancher UI includes a new Multitenancy Management menu option for each managed cluster.

      Rancher Extensions - Multitenancy Management menu

5 Provision a tenant cluster

With the Kamaji Operator, the Kamaji Console, and the Kamaji Extension deployed to your Kamaji Admin Cluster, you are ready to provision tenant (downstream) clusters.

5.1 Deploy a tenant control plane

The first step to provision a tenant cluster is to create a tenant control plane (TCP) in the Kamaji Admin Cluster.

Important
Important

Tenant control plane pods are exposed by a load balancer service that is the 'ControlPlaneEndpoint' for the worker nodes. Make sure your Kamaji Admin Cluster supports the creation of the 'LoadBalancer' service type and that IP addresses can be provisioned and assigned. Otherwise, the Kamaji Operator will wait indefinitely to deploy your tenant control plane.

  1. In the SUSE Rancher UI, select your Kamaji Admin Cluster.

  2. Select Multitenancy Management and click Kamaji Console.

    Rancher Extensions - launch Kamaji Console

    The Kamaji Console opens in another tab or window of your browser.

  3. Log in to the Kamaji Console UI with the e-mail address and password you set during deployment.

  4. In the Kamaji Console, select Tenant Control Planes in the left panel, then click Create.

    Tenant Control Planes - Create
  5. You are presented a sample TCP YAML file for configuring the tenant control plane. Adjust Kubernetes version, ServiceType, and other values for your infrastructure.

    Create TCP editor

    For convenience, a sample TCP YAML file is provided below.

    apiVersion: kamaji.clastix.io/v1alpha1
    kind: TenantControlPlane
    metadata:
      name: sample
      namespace: default
    spec:
      dataStore: default
      controlPlane:
        deployment:
          replicas: 2
        service:
          serviceType: LoadBalancer
      kubernetes:
        version: v1.25.4
        kubelet:
          cgroupfs: systemd
      networkProfile:
        port: 6443
      addons:
        coreDNS: {}
        kubeProxy: {}
        konnectivity:
          server:
            port: 8132
            version: v0.0.32
          agent:
            version: v0.0.32
    Note
    Note

    If you are not using the default namespace, make sure the namespace exists before applying the configuration.

  6. Click Create to deploy the tenant control plane.

    The Kamaji Operator creates the tenant control plane as declared in the TCP YAML file, including Secrets to store the certificates used to access the tenant cluster.

  7. You can see an overview of the 'sample' tenant control plane that was created in the Kamaji Console.

    Tenant Control Plane overview
  8. Click VIEW KUBECONFIG to retrieve the Kubeconfig for your tenant control plane and save it as the file, default-sample.kubeconfig.

5.2 Prepare worker nodes

Be sure the bare metal or virtual machines you use as your worker nodes have the following components installed:

  • containerd

  • crictl

  • kubectl

  • kubelet

  • kubeadm

Tip
Tip

The nodesetup.sh script can automate installation of these prerequisites for Ubuntu 22.04 and can be modified for your preferred operating system.

5.3 Join worker nodes

The tenant control plane is made of pods running in the Kamaji Admin Cluster. At this point, the tenant cluster has no worker nodes. So, the next step is to join some worker nodes to the tenant control plane.

Kamaji leverages the Cluster Management API (CAPI) project. This allows you to create the tenant clusters, including worker nodes, in a completely declarative way. Refer to the Kamaji CAPI providers repository to learn more about supported providers.

The current approach for joining nodes is to run a kubeadm command on each node.

  1. Open the command line on your Linux workstation.

  2. Store the IP address (or host name) of each node in a variable.

    WORKER0=<address of first node>
    WORKER1=<address of second node>
    WORKER2=<address of third node>
  3. Store the join command in a variable.

    JOIN_CMD=$(echo "sudo ")$(kubeadm --kubeconfig=default-sample.kubeconfig token create --print-join-command)
  4. Use a loop to log in to and run the join command on each node.

    HOSTS=(${WORKER0} ${WORKER1} ${WORKER2})
    for i in "${!HOSTS[@]}"; do
      HOST=${HOSTS[$i]}
      ssh ${USER}@${HOST} -t ${JOIN_CMD};
    done
  5. You can check the status of the worker nodes from the command line with:

    kubectl --kubeconfig=default-sample.kubeconfig get nodes
Tip
Tip

This process can be further automated to handle the node prerequisites and joining. See yaki nodesetup.sh script, which you could modify for your preferred operating system.

5.4 Install the Cluster Network Interface

Your tenant cluster also needs a Container Network Interface (CNI) plugin. The CNI plugin enables seamless communication and connectivity between containers and external networks. For this guide, you use the Calico CNI.

  1. Download the latest, stable Calico manifest to your Linux workstation.

    For example:

    curl https://raw.githubusercontent.com/projectcalico/calico/v3.24.1/manifests/calico.yaml -O
  2. Apply the manifest to your tenant cluster.

    kubectl --kubeconfig=default-sample.kubeconfig apply -f calico.yaml
    Tip
    Tip

    You can check the status from the command line:

    kubectl --kubeconfig=default-sample.kubeconfig get nodes
  3. When the nodes are ready, they are visible to you in the Kamaji Console.

    Tenant Nodes in the Kamaji Console

6 Import the tenant cluster into SUSE Rancher

Bring your tenant clusters into SUSE Rancher for unified management and oversight of your Kubernetes landscape.

  1. Log in to the SUSE Rancher UI.

  2. In Cluster Management, select Clusters.

  3. Click Import Existing.

  4. Enter a 'Cluster Name'.

  5. Click Create.

  6. Copy the kubectl command displayed in the SUSE Rancher UI to your clipboard and run it against the tenant cluster on the command line of your Linux workstation.

    Warning
    Warning

    Make sure you use the Kubeconfig related to the tenant cluster you wish to import.

  7. Your tenant cluster is in a 'Pending' state while SUSE Rancher deploys resources to manage it. This may take a few minutes.

  8. When the state changes to 'Active', your tenant cluster has been imported.

    Tenant clusters imported into Rancher
  9. You now have a unified view and central management of your Kubernetes landscape with SUSE Rancher.

7 Summary

SUSE Rancher Prime empowers enterprises to streamline multi-cluster Kubernetes operations everywhere with unified security, policy, and user management. CLASTIX Kamaji delivers a highly scalable and high-density Kubernetes control plane infrastructure with reduced operational overhead, yielding faster deployment, configuration, upgrades, and maintenance. Together, SUSE and CLASTIX enable enterprises, managed services providers, and others to leverage Kubernetes resources more efficiently and enable secure Kubernetes-as-a-Service to multiple departments and clients.

In this guide, you learned how to seamlessly deploy CLASTIX Kamaji into your SUSE Rancher Prime Kubernetes landscape, create tenant clusters, and import them into SUSE Rancher for management.

Continue your journey by watching Rancher and Kamaji: solving multi-tenancy challenges in the Kubernetes world.

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5. COMBINING DOCUMENTS

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The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements".

6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation’s users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document’s Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

8. TRANSLATION

Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

9. TERMINATION

You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

ADDENDUM: How to use this License for your documents

Copyright (c) YEAR YOUR NAME.
   Permission is granted to copy, distribute and/or modify this document
   under the terms of the GNU Free Documentation License, Version 1.2
   or any later version published by the Free Software Foundation;
   with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
   A copy of the license is included in the section entitled “GNU
   Free Documentation License”.

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “ with…​Texts.” line with this:

with the Invariant Sections being LIST THEIR TITLES, with the
   Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.