Meet Longhorn a cloud native distributed block storage for Kubernetes

Cloud native distributed block storage for Kubernetes

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Prerequisites:

Minimum Hardware requirements:

• 3 nodes
• 4 vCPUs per node
• 4 GiB per node
• SSD/NVMe or similar performance block device on the node for storage

Installation Requirements:

• A container runtime compatible with Kubernetes (Docker v1.13+, containerd v1.3.7+, etc.)
• Kubernetes >= v1.21
• open-iscsi is installed, and the iscsid daemon is running on all the nodes.
• RWX support requires that each node has a NFSv4 client installed.
• The host filesystem supports the file extents feature to store the data. Currently longhorn support:
  • ext4
  • XFS
• bash, curl, findmnt, grep, awk, blkid, lsblk must be installed.
• Mount propagation must be enabled.

Install dependencies:

Install nfs-common, open-iscsi & ensure daemon is running on all the nodes.

{
sudo apt update
sudo apt install -y nfs-common open-iscsi
sudo systemctl enable open-iscsi --now
systemctl status iscsid
}

Run the Environment Check Script:

# For AMD64 platform
curl -sSfL -o longhornctl https://github.com/longhorn/cli/releases/download/v1.10.0/longhornctl-linux-amd64

# For ARM platform
curl -sSfL -o longhornctl https://github.com/longhorn/cli/releases/download/v1.10.0/longhornctl-linux-arm64

chmod +x longhornctl
./longhornctl check preflight --kubeconfig=.kube/config

Installing Longhorn with Helm:

Helm v3.0+ must be installed on your workstation.

Add the Longhorn Helm repository:

helm repo add longhorn https://charts.longhorn.io

Fetch the latest charts from the repository:

helm repo update

Retrieve the package from longhorn repository, and download it locally:

helm fetch longhorn/longhorn --untar

Install Longhorn in the longhorn namespace:

helm install longhorn longhorn/longhorn --values longhorn/values.yaml -n longhorn-system --create-namespace --version 1.10.0

To confirm that the deployment succeeded, run:

kubectl -n longhorn-system get pod

Enabling basic authentication with ingress for longhorn UI

Authentication is not enabled by default for kubectl and Helm installations.

Note : Create a basic authentication file auth. It’s important the file generated is named auth (actually - that the secret has a key data.auth), otherwise the Ingress returns a 503.

USER=<USERNAME_HERE>; PASSWORD=<PASSWORD_HERE>; echo "${USER}:$(openssl passwd -stdin -apr1 <<< ${PASSWORD})" >> auth

Create a secret:

kubectl -n longhorn-system create secret generic basic-auth --from-file=auth

Create the ingress resource:

cat <<EOF | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: longhorn-frontend
  namespace: longhorn-system
  annotations:
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    nginx.ingress.kubernetes.io/auth-realm: "Authentication Required"
    # cert-manager.io/cluster-issuer: "letsencrypt-prod"
    # nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  tls:
    - hosts:
        - longhorn.mkbn.in
      secretName: tls-longhorn-frontend
  rules:
    - host: longhorn.mkbn.in
      http:
        paths:
        - path: /
          pathType: Prefix
          backend:
            service:
              name: longhorn-frontend
              port:
                number: 80
EOF

Accessing the Longhorn UI:

https://longhorn.mkbn.in

Accessing without ingress:

Get the Longhorn’s external service IP:

kubectl -n longhorn-system get svc

Use CLUSTER-IP of the longhorn-frontend to access the Longhorn UI using port forward:

kubectl port-forward svc/longhorn-frontend 8080:80 -n longhorn-system

Create a demo StatefulSet using the default storage class:

Check out the github repo for code sample.

kubectl apply -f gitea-demo/gitea.yaml

🔗 Reference Links:

• longhorn

• Ingress