Efficient Multi-Tenancy with CLASTIX Kamaji and Rancher Prime by SUSE #

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.

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

For this guide, you need the following:

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 Rancher Prime by SUSE for centralized management of your Kubernetes landscape. Rancher Prime enables global administrators to streamline operations, improve consistency and security through an intuitive interface or through GitOps-driven workflows.

CLASTIX Kamaji is available through the Rancher App catalog. This curated collection of software, packaged and maintained as Helm charts, makes it easy to install software directly from the Rancher user interface (UI). Kamaji consists of the Kamaji Operator and the Kamaji Console, both of which are available in the Rancher App catalog.

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

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

5.1 Deploying 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

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 Rancher UI, select your Kamaji Admin Cluster.

2. Select Multitenancy Management and click 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.

   

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.

   

   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

   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.

   

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

5.2 Preparing worker nodes #

 

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

• containerd

• crictl

• kubectl

• kubelet

• kubeadm

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 Joining 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

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.

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

Rancher Prime by SUSE 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 Rancher Prime by SUSE Kubernetes landscape, create tenant clusters, and import them into Rancher for unified and streamlined management.

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

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