Meet Longhorn a cloud native distributed block storage for Kubernetes

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:

Note: jq[sudo apt install -y jq] maybe required to be installed locally prior to running env check script.

curl -sSfL https://raw.githubusercontent.com/longhorn/longhorn/v1.5.1/scripts/environment_check.sh | bash

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 /tmp/longhorn/values.yaml -n longhorn --create-namespace --version 1.7.2

To confirm that the deployment succeeded, run:

kubectl -n longhorn get pod

Accessing the Longhorn UI:

Get the Longhorn’s external service IP:

kubectl -n longhorn 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

Enabling basic authentication with ingress for longhorn UI

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

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 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-ingress
  namespace: longhorn
  annotations:
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/ssl-redirect: 'false'
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required '
    nginx.ingress.kubernetes.io/proxy-body-size: 10000m
spec:
  rules:
  - http:
      paths:
      - pathType: Prefix
        path: "/"
        backend:
          service:
            name: longhorn-frontend
            port:
              number: 80
EOF

Reference Links:

• longhorn

• Ingress