You can install Longhorn on any Kubernetes cluster using kubectl with this command:

  1. kubectl apply -f https://raw.githubusercontent.com/longhorn/longhorn/master/deploy/longhorn.yaml

One way to monitor the progress of the installation is to watch Pods being created in the longhorn-system namespace:

  1. kubectl get pods \
  2. --namespace longhorn-system \
  3. --watch

The following items will be deployed to Kubernetes

Namespace: longhorn-system

All Longhorn bits will be scoped to this namespace.

ServiceAccount: longhorn-service-account

Service account is created in the longhorn-system namespace.

ClusterRole: longhorn-role

This role will have access to:

  • In apiextension.k8s.io (All verbs)
    • customresourcedefinitions
  • In core (All verbs)
    • pods
      • /logs
    • events
    • persistentVolumes
    • persistentVolumeClaims
      • /status
    • nodes
    • proxy/nodes
    • secrets
    • services
    • endpoints
    • configMaps
  • In core
    • namespaces (get, list)
  • In apps (All Verbs)
    • daemonsets
    • statefulSets
    • deployments
  • In batch (All Verbs)
    • jobs
    • cronjobs
  • In storage.k8s.io (All verbs)
    • storageclasses
    • volumeattachments
    • csinodes
    • csidrivers
  • In coordination.k8s.io
    • leases
  • In longhorn.rancher.io (All verbs, deprecated after v0.7.0)
    • volumes
    • engines
    • replicas
    • settings
    • engineimages
    • nodes
    • instancemanagers

ClusterRoleBinding: longhorn-bind

This connects the longhorn-role to the longhorn-service-account in the longhorn-system namespace

CustomResourceDefinitions

The following CustomResourceDefinitions will be installed

  • In longhorn.io
    • engines
    • replicas
    • settings
    • volumes
    • engineimages
    • nodes
    • instancemanagers

Kubernetes API Objects

  • A config map with the default settings
  • The longhorn-manager DaemonSet
  • The longhorn-backend service exposing the longhorn-manager DaemonSet internally to Kubernetes
  • The longhorn-ui Deployment
  • The longhorn-fronend service exposing the longhorn-ui internally to Kubernetes
  • The longhorn-driver-deployer that deploys the CSI driver
  • The longhorn StorageClass

At this point Longhorn should be ready to use.