Cluster Management with Rancher and Longhorn

This guide covers deploying Rancher for comprehensive cluster management and Longhorn for cloud-native distributed storage in your K3s cluster.

Deploying Rancher

Add Rancher Helm Repository and Create Namespace

helm repo add rancher-latest https://releases.rancher.com/server-charts/stable
kubectl create namespace cattle-system

Since Traefik is already deployed, Rancher will utilize it for ingress. Deploy Rancher with Helm:

helm install rancher rancher-stable/rancher \
  --namespace cattle-system \
  --set hostname=rancher.k3s.your.domain \
  --set tls=external \
  --set replicas=3

Create Ingress for Rancher

Create an ingress.yml file with the following configuration:

1
apiVersion: traefik.io/v1alpha1
2
kind: IngressRoute
3
metadata:
4
  name: rancher
5
  namespace: cattle-system
6
spec:
7
  entryPoints:
8
    - websecure
9
  routes:
10
    - match: Host(`rancher.k3s.your.domain`)
11
      kind: Rule
12
      services:
13
        - name: rancher
14
          port: 443
15
      middlewares:
16
        - name: default-headers
17
  tls:
18
    secretName: k3s-your-domain-tls

Apply the ingress configuration:

kubectl apply -f ingress.yml

Now, you should be able to manage your cluster from https://rancher.k3s.your.domain.

Rancher Dashboard

Deploying Longhorn

If you want to use cloud-ready drive shared storage, follow these steps:

Install Required Packages

Only on the VMs you want to deploy longhorn:

sudo apt update && sudo apt install -y open-iscsi nfs-common

Enable iSCSI

sudo systemctl enable iscsid
sudo systemctl start iscsid

Add Longhorn Label on Nodes

A minimum of three nodes are required for High Availability. In this setup, we will use three worker nodes:

kubectl label node k3s-worker-1 storage.longhorn.io/node=true
kubectl label node k3s-worker-2 storage.longhorn.io/node=true
kubectl label node k3s-worker-3 storage.longhorn.io/node=true

Deploy Longhorn

Modified to use storage.longhorn.io/node=true label:

kubectl apply -f https://raw.githubusercontent.com/meroxdotdev/merox.docs/refs/heads/master/K3S/cluster-deployment/longhorn.yaml

Verify Deployment

kubectl get pods --namespace longhorn-system --watch

Print Confirmation

kubectl get nodes
kubectl get svc -n longhorn-system

Exposing Longhorn with Traefik

Create Middleware Configuration

Create a middleware.yml file:

1
apiVersion: traefik.io/v1alpha1
2
kind: Middleware
3
metadata:
4
  name: longhorn-headers
5
  namespace: longhorn-system
6
spec:
7
  headers:
8
    customRequestHeaders:
9
      X-Forwarded-Proto: "https"

Setup Ingress

Create an ingress.yml file:

1
apiVersion: networking.k8s.io/v1
2
kind: Ingress
3
metadata:
4
  name: longhorn-ingress
5
  namespace: longhorn-system
6
  annotations:
7
    traefik.ingress.kubernetes.io/router.entrypoints: websecure
8
    traefik.ingress.kubernetes.io/router.tls: "true"
9
    traefik.ingress.kubernetes.io/router.middlewares: longhorn-system-longhorn-headers@kubernetescrd
10
spec:
11
  rules:
12
  - host: storage.k3s.your.domain
13
    http:
14
      paths:
15
      - path: /
16
        pathType: Prefix
17
        backend:
18
          service:
19
            name: longhorn-frontend
20
            port:
21
              number: 80
22
  tls:
23
  - hosts:
24
    - storage.k3s.your.domain
25
    secretName: k3s-your-domain-tls

Longhorn Storage Dashboard

Next Steps

Explore the Advanced Resources guide for additional tools including NFS storage, monitoring solutions, ArgoCD for GitOps, and cluster upgrade procedures.