Going back to the end of the previous sub-chapter, we introduce the Rook storage provider. It is inserted between the hard disk of the VMs, always based on NFS, and the Kubernetes cluster. As said previously, NFS allows remote hosts to mount filesystems over a network and interact with those filesystems as though they are mounted locally. This enables system administrators to consolidate resources onto centralized servers on the network. As a prerequisite, NFS client packages must be installed on all nodes (nfs-utils on CentOS), where Kubernetes might run pods with NFS mounted. However, the official guide can be found here.

Deploy NFS Operator

First deploy the Rook NFS operator using the following commands

# Clone the repository and change directory
$ git clone --single-branch --branch v1.5.3 https://github.com/rook/rook.git
$ cd rook/cluster/examples/kubernetes/nfs

# Then launch
$ kubectl create -f common.yaml -f operator.yaml

# Check if the operator is up and running
$ kubectl get pod -n rook-nfs-system
NAME                                READY   STATUS    RESTARTS   AGE
rook-nfs-operator-f79889845-8r5kq   1/1     Running   0          11m

Create and Initialize NFS Server

It is recommended that you create Pod Security Policies first. To do this, you can use the psp.yaml file already present in the folder with the usual command

$ kubectl create -f psp.yaml
podsecuritypolicy.policy/rook-nfs-policy created

# To get it
$ kubectl get psp
NAME              PRIV   CAPS                           SELINUX    RUNASUSER   FSGROUP    SUPGROUP   READONLYROOTFS   VOLUMES
rook-nfs-policy   true   DAC_READ_SEARCH,SYS_RESOURCE   RunAsAny   RunAsAny    RunAsAny   RunAsAny   false            configMap,downwardAPI,emptyDir,persistentVolumeClaim,secret,hostPath