#k0rdent Cluster Manager (KCM)

#Overview

k0rdent Cluster Manager is part of k0rdent which is focused on delivering a open source approach to providing an enterprise grade multi-cluster kubernetes management solution based entirely on standard open source tooling that works across private or public clouds.

#Documentation

Detailed documentation is available in k0rdent Docs

#Installation

#TL;DR

helm install kcm oci://ghcr.io/k0rdent/kcm/charts/kcm -n kcm-system --create-namespace

Then follow the Deploy a cluster deployment guide to create a cluster deployment.

[!NOTE] The KCM installation using Kubernetes manifests does not allow customization of the deployment. To apply a custom KCM configuration, install KCM using the Helm chart.

#Development guide

See Install KCM for development purposes.

#Software Prerequisites

KCM requires the following:

1. Existing management cluster (minimum required kubernetes version 1.28.0).
2. kubectl CLI installed locally.

Optionally, the following CLIs may be helpful:

1. helm (required only when installing KCM using helm).
2. clusterctl (to handle the lifecycle of the cluster deployments).

#Providers configuration

Full details on the provider configuration can be found in the k0rdent Docs, see Documentation

#k0rdent Installation

export KUBECONFIG=<path-to-management-kubeconfig>

helm install kcm oci://ghcr.io/k0rdent/kcm/charts/kcm --version <kcm-version> -n kcm-system --create-namespace

#Extended Management configuration

By default, kcm is being deployed with the following configuration:

apiVersion: k0rdent.mirantis.com/v1beta1
kind: Management
metadata:
  name: kcm
spec:
  providers:
  - name: cluster-api-provider-k0sproject-k0smotron
  - name: cluster-api-provider-azure
  - name: cluster-api-provider-vsphere
  - name: cluster-api-provider-aws
  - name: cluster-api-provider-openstack
  - name: cluster-api-provider-docker
  - name: cluster-api-provider-gcp
  - name: cluster-api-provider-ipam
  - name: cluster-api-provider-infoblox
  - name: projectsveltos
  release: kcm-<dashed-kcm-version>

There are two options to override the default management configuration of KCM:

1. Update the Management object after the KCM installation using kubectl:

   kubectl --kubeconfig <path-to-management-kubeconfig> edit management

2. Deploy KCM skipping the default Management object creation and provide your own Management configuration:

   • Create management.yaml file and configure core components and providers. See Management API.

   • Specify --create-management=false controller argument and install KCM:

   If installing using helm add the following parameter to the helm install command:

   --set="controller.createManagement=false"

   • Create kcm Management object after KCM installation:

   kubectl --kubeconfig <path-to-management-kubeconfig> create -f management.yaml

#Create a ClusterDeployment

To create a ClusterDeployment:

1. Create Credential object with all credentials required.

   See Credential system docs for more information regarding this object.

2. Select the ClusterTemplate you want to use for the deployment. To list all available templates, run:

export KUBECONFIG=<path-to-management-kubeconfig>

kubectl get clustertemplate -n kcm-system

If you want to deploy hosted control plane template, make sure to check additional notes on Hosted control plane in k0rdent Docs, see Documentation.

2. Create the file with the ClusterDeployment configuration:

[!NOTE] Substitute the parameters enclosed in angle brackets with the corresponding values. Enable the dryRun flag if required. For details, see Dryrun.

apiVersion: k0rdent.mirantis.com/v1beta1
kind: ClusterDeployment
metadata:
  name: <cluster-name>
  namespace: <cluster-namespace>
spec:
  template: <template-name>
  credential: <credential-name>
  dryRun: <true/false>
  config:
    <cluster-configuration>

3. Create the ClusterDeployment object:

kubectl create -f clusterdeployment.yaml

4. Check the status of the newly created ClusterDeployment object:

kubectl -n <clusterdeployment-namespace> get clusterdeployments <clusterdeployment-name> -o=yaml

5. Wait for infrastructure to be provisioned and the cluster to be deployed (the provisioning starts only when spec.dryRun is disabled):

kubectl -n <clusterdeployment-namespace> get cluster <clusterdeployment-name> -o=yaml

[!NOTE] You may also watch the process with the clusterctl describe command (requires the clusterctl CLI to be installed): clusterctl describe cluster <clusterdeployment-name> -n <clusterdeployment-namespace> --show-conditions all

6. Retrieve the kubeconfig of your cluster deployment:

kubectl get secret -n kcm-system <clusterdeployment-name>-kubeconfig -o go-template='{{.data.value|base64decode}}' > kubeconfig

#Dry run

KCM ClusterDeployment supports two modes: with and without (default) dryRun.

If no configuration (spec.config) provided, the ClusterDeployment object will be populated with defaults (default configuration can be found in the corresponding Template status) and automatically marked as dryRun.

After you adjust your configuration and ensure that it passes validation (TemplateReady condition from status.conditions), remove the spec.dryRun flag to proceed with the deployment.

#Cleanup

1. Remove the Management object:

[!NOTE] Make sure you have no KCM ClusterDeployment objects left in the cluster prior to Management deletion

kubectl delete management.k0rdent kcm

2. Remove the kcm Helm release:

helm uninstall kcm -n kcm-system

3. Remove the kcm-system namespace:

kubectl delete ns kcm-system