Prerequisites

• Your workstation: Install Helm v3.0 or later.
• Kubernetes cluster:

  • Ensure that each node fulfills the installation requirements.

  • Install the Flux CLI and controllers.

  • Bootstrap Flux with GitHub using the Flux CLI. Run the following commands to export your GitHub personal access token (PAT) as an environment variable, deploy the Flux controllers on your cluster, and configure the controllers to sync the cluster state from the specified GitHub repository.

    export GITHUB_TOKEN=<gh-token>
    flux bootstrap github \
      --token-auth \
      --owner=<github_username> \
      --repository=<github_repo_name> \
      --branch=<branch_name> \
      --path=<folder_path_within_repo> \
      --personal
    

Use this script to check the Longhorn environment for potential issues.

Installing Longhorn

1. Create a HelmRepository custom resource (CR) that points to the Longhorn Helm chart URL.

   kubectl create ns longhorn-system
   flux create source helm longhorn-repo \
     --url=https://charts.longhorn.io \
     --namespace=longhorn-system \
     --export > helmrepo.yaml
   kubectl apply -f helmrepo.yaml
   

2. Create a HelmRelease CR that references the HelmRepository and specifies the version of the Longhorn Helm chart to be installed.

   flux create helmrelease longhorn-release \
     --chart=longhorn \
     --source=HelmRepository/longhorn-repo \
     --chart-version=v1.6.1 \
     --namespace=longhorn-system \
     --export > helmrelease.yaml
   kubectl apply -f helmrelease.yaml
   

3. Verify that the HelmRelease CR was created and synced successfully.

   flux get helmrelease longhorn-release -n longhorn-system
   

4. Verify that Longhorn was installed successfully.

   kubectl -n longhorn-system get pod
   

   Example of a successful Longhorn installation:

   NAME                                                READY   STATUS    RESTARTS   AGE
   longhorn-ui-b7c844b49-w25g5                         1/1     Running   0          2m41s
   longhorn-manager-pzgsp                              1/1     Running   0          2m41s
   longhorn-driver-deployer-6bd59c9f76-lqczw           1/1     Running   0          2m41s
   longhorn-csi-plugin-mbwqz                           2/2     Running   0          100s
   csi-snapshotter-588457fcdf-22bqp                    1/1     Running   0          100s
   csi-snapshotter-588457fcdf-2wd6g                    1/1     Running   0          100s
   csi-provisioner-869bdc4b79-mzrwf                    1/1     Running   0          101s
   csi-provisioner-869bdc4b79-klgfm                    1/1     Running   0          101s
   csi-resizer-6d8cf5f99f-fd2ck                        1/1     Running   0          101s
   csi-provisioner-869bdc4b79-j46rx                    1/1     Running   0          101s
   csi-snapshotter-588457fcdf-bvjdt                    1/1     Running   0          100s
   csi-resizer-6d8cf5f99f-68cw7                        1/1     Running   0          101s
   csi-attacher-7bf4b7f996-df8v6                       1/1     Running   0          101s
   csi-attacher-7bf4b7f996-g9cwc                       1/1     Running   0          101s
   csi-attacher-7bf4b7f996-8l9sw                       1/1     Running   0          101s
   csi-resizer-6d8cf5f99f-smdjw                        1/1     Running   0          101s
   instance-manager-b34d5db1fe1e2d52bcfb308be3166cfc   1/1     Running   0          114s
   engine-image-ei-df38d2e5-cv6nc                      1/1     Running   0          114s
   

5. Create an NGINX Ingress controller with basic authentication to access the Longhorn UI. Authentication to the Longhorn UI is not enabled by default.

6. Access the Longhorn UI.

Continuous Operations via GitOps

You can commit and push exported manifests to your GitOps repository.

```bash
git add helmrepo.yaml helmrelease.yaml
git commit -m "Add HelmRepository and HelmRelease for Longhorn installation"
git push origin <branch_name>
```

Afterwards, you can modify the HelmRelease and HelmRepository CRs by editing the YAML manifests in your GitOps repository. Flux automatically detects and applies the changes without requiring direct access to your Kubernetes cluster.