In this section, you will learn how to install Longhorn with the HelmChart controller built into RKE2 and K3s.

Prerequisites

• Kubernetes cluster: Ensure that each node fulfills the installation requirements. Cluster should be running RKE2 or K3s.

Longhorn Command Line Tool can be used to check the Longhorn environment for potential issues.

Installing Longhorn

Note:

• The initial settings for Longhorn can be customized using Helm options or by editing the deployment configuration file.
• For Kubernetes < v1.25, if your cluster still enables Pod Security Policy admission controller, set the helm value enablePSP to true to install longhorn-psp PodSecurityPolicy resource which allows privileged Longhorn pods to start.

1. Create a HelmChart yaml file similar to this:

   apiVersion: helm.cattle.io/v1
   kind: HelmChart
   metadata:
     annotations:
       helmcharts.cattle.io/managed-by: helm-controller
     finalizers:
     - wrangler.cattle.io/on-helm-chart-remove
     generation: 1
     name: longhorn-install
     namespace: default
   spec:
     version: v1.9.0
     chart: longhorn
     repo: https://charts.longhorn.io
     failurePolicy: abort
     targetNamespace: longhorn-system
     createNamespace: true
   
   

   IMPORTANT! Ensure that spec.failurePolicy is set to “abort”. The only other value is the default: “reinstall”, which performs an uninstall of Longhorn. With “abort”, it retries periodically, giving the user a chance to fix the problem.

   Note: Rather than specify the repo, version, and chart name, the yaml can also use an image of the charts themselves:

   spec:
     chartContent:  <tarball of chart directory | base64 -w 0>
   

   For full details see the HelmChart controller docs: https://docs.rke2.io/helm or https://docs.k3s.io/helm.

2. Apply it to create the HelmChart CR and an installation job:

   $ kubectl apply -f helmchart_repo_install.yaml
   helmchart.helm.cattle.io/longhorn-install created
   
   

   Note: Deleting the helmchart CR will initiate an uninstall of Longhorn.

3. To show the created resources:

   $ kubectl get jobs
   NAME                            COMPLETIONS   DURATION   AGE
   helm-install-longhorn-install   0/1           8s         8s
   
   $ kubectl get pods
   NAME                                  READY   STATUS      RESTARTS   AGE
   helm-install-longhorn-install-lngm8   0/1     Completed   0          25s
   
   $ kubectl get helmcharts
   NAME               JOB                     CHART      TARGETNAMESPACE   VERSION   REPO                         HELMVERSION   BOOTSTRAP
   longhorn-install   helm-install-longhorn   longhorn   longhorn-system   v1.9.0    https://charts.longhorn.io
   
   

4. To confirm that the deployment succeeded, run:

   kubectl -n longhorn-system get pod
   

   The result should look like the following:

   NAME                                                READY   STATUS    RESTARTS      AGE
   csi-attacher-85c7684cfd-67kqc                       1/1     Running   0             29m
   csi-attacher-85c7684cfd-jbddj                       1/1     Running   0             29m
   csi-attacher-85c7684cfd-t85bw                       1/1     Running   0             29m
   csi-provisioner-68cdb8b96-46d9q                     1/1     Running   0             29m
   csi-provisioner-68cdb8b96-dgf5f                     1/1     Running   0             29m
   csi-provisioner-68cdb8b96-mh8q7                     1/1     Running   0             29m
   csi-resizer-86dd765b9-d27cs                         1/1     Running   0             29m
   csi-resizer-86dd765b9-scqxm                         1/1     Running   0             29m
   csi-resizer-86dd765b9-zpcv7                         1/1     Running   0             29m
   csi-snapshotter-65b46b8749-dtvh2                    1/1     Running   0             29m
   csi-snapshotter-65b46b8749-g67fn                    1/1     Running   0             29m
   csi-snapshotter-65b46b8749-nfgzm                    1/1     Running   0             29m
   engine-image-ei-221c9c21-gd5d6                      1/1     Running   0             29m
   engine-image-ei-221c9c21-v6clp                      1/1     Running   0             29m
   engine-image-ei-221c9c21-zzdrt                      1/1     Running   0             29m
   instance-manager-77d11dda6091967f9b30011c9876341b   1/1     Running   0             29m
   instance-manager-870c250b69a4fe01382ed46156d33f47   1/1     Running   0             29m
   instance-manager-a4099c5ce28b423c3cc2667906f4b0b4   1/1     Running   0             29m
   longhorn-csi-plugin-jfbh5                           3/3     Running   0             29m
   longhorn-csi-plugin-w768w                           3/3     Running   0             29m
   longhorn-csi-plugin-xcghm                           3/3     Running   0             29m
   longhorn-driver-deployer-586bc86bf9-bkwk6           1/1     Running   0             30m
   longhorn-manager-c4xtv                              1/1     Running   1 (30m ago)   30m
   longhorn-manager-kgqts                              1/1     Running   0             30m
   longhorn-manager-n8xdr                              1/1     Running   0             30m
   longhorn-ui-69667f9678-2lvxn                        1/1     Running   0             30m
   longhorn-ui-69667f9678-2xmc9                        1/1     Running   0             30m
   
   

5. To enable access to the Longhorn UI, you need to set up an Ingress controller. Authentication to the Longhorn UI is not enabled by default. For information on creating an NGINX Ingress controller with basic authentication, refer to this section.

6. Access the Longhorn UI using these steps.