NFS Storage

To manage volumes based on the NFS (Network File System) protocol, you can use the csi-nfs module, which allows the creation of a StorageClass through the creation of custom NFSStorageClass resources.

Enabling the module

To enable the csi-nfs module, apply the following resource:

d8 k apply -f - <<EOF
apiVersion: deckhouse.io/v1alpha1
kind: ModuleConfig
metadata:
  name: csi-nfs
spec:
  enabled: true
  version: 1
EOF

Wait until the csi-nfs module transitions to the Ready status. To check the status, run the following command:

d8 k get module csi-nfs -w

In the output, you should see information about the csi-nfs module:

NAME      WEIGHT   STATE     SOURCE     STAGE   STATUS
csi-nfs   910      Enabled   Embedded           Ready

Creating the StorageClass

To create a StorageClass, you need to use the NFSStorageClass resource. Manually creating a StorageClass without NFSStorageClass may lead to errors.

Example of creating a StorageClass based on NFS:

d8 k apply -f - <<EOF
apiVersion: storage.deckhouse.io/v1alpha1
kind: NFSStorageClass
metadata:
  name: nfs-storage-class
spec:
  connection:
    # Address of the NFS server.
    host: 10.223.187.3
    # Path to the mount point on the NFS server.
    share: /
    # Version of the NFS server.
    nfsVersion: "4.1"
  # Reclaim policy when deleting PVC.
  # Allowed values:
  # - Delete (PVC deletion will also delete PV and data on the NFS server).
  # - Retain (PVC deletion will not delete PV or data on the NFS server, requiring manual removal by the user).
  # [Learn more...](https://kubernetes.io/docs/concepts/storage/persistent-volumes/#reclaiming)
  reclaimPolicy: Delete
  # Volume creation mode.
  # Allowed values: "Immediate", "WaitForFirstConsumer".
  # [Learn more...](https://kubernetes.io/docs/concepts/storage/storage-classes/#volume-binding-mode)
  volumeBindingMode: WaitForFirstConsumer
EOF

Check that the created NFSStorageClass resource has transitioned to the Created phase by running the following command:

d8 k get NFSStorageClass nfs-storage-class -w

In the output, you should see information about the created NFSStorageClass resource:

NAME                PHASE     AGE
nfs-storage-class   Created   1h

Check that the corresponding StorageClass has been generated by running the following command:

d8 k get sc nfs-storage-class

In the output, you should see information about the generated StorageClass:

NAME                PROVISIONER      RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
nfs-storage-class   nfs.csi.k8s.io   Delete          WaitForFirstConsumer   true                   1h

If the StorageClass named nfs-storage-class appears, it means the csi-nfs module has been configured successfully. Users can now create PersistentVolumes by specifying the nfs-storage-class StorageClass.

For each PersistentVolume resource, a directory <share-directory>/<PersistentVolume-name> will be created.

Checking module functionality

To check the functionality of the csi-nfs module, you need to verify the pod statuses in the d8-csi-nfs namespace. All pods should be in the Running or Completed state, and the csi-nfs pods should be running on all nodes.

You can check the module’s functionality with the following command:

d8 k -n d8-csi-nfs get pod -owide -w

In the output, you should see a list of all pods in the d8-csi-nfs namespace.

NAME                             READY   STATUS    RESTARTS   AGE   IP             NODE       NOMINATED NODE   READINESS GATES
controller-547979bdc7-5frcl      1/1     Running   0          1h    10.111.2.84    master     <none>           <none>
csi-controller-5c6bd5c85-wzwmk   6/6     Running   0          1h    172.18.18.50   master     <none>           <none>
webhooks-7b5bf9dbdb-m5wxb        1/1     Running   0          1h    10.111.0.16    master     <none>           <none>
csi-nfs-8mpcd                    2/2     Running   0          1h    172.18.18.50   master     <none>           <none>
csi-nfs-n6sks                    2/2     Running   0          1h    172.18.18.51   worker-1   <none>           <none>