NFS Subdir External Provisioner Setup Guide

Learn how to set up dynamic volume provisioning in Kubernetes using an NFS server.

1. Resource Relationship Diagram

This shows how the main components of the NFS provisioner interact.

    graph TD
    subgraph K8S_Cluster[Kubernetes Cluster]
        PVC[PersistentVolumeClaim] -- "1. Request" --> SC[StorageClass: nfs-client]
        SC -- "2. Watch" --> DEP[Deployment: nfs-provisioner]
        DEP -- "4. Create" --> PV[PersistentVolume]
        PV --- PVC
    end

    subgraph External_Storage[Remote Storage]
        DEP -- "3. Create directory" --> NFS[(NFS Server)]
    end

    RBAC[RBAC: SA / ClusterRole] --> DEP
  

Roles of the Main Resources

2. Dynamic Provisioning Workflow

This is what happens internally when a user creates a PVC.

    sequenceDiagram
    participant U as User
    participant P as NFS Provisioner
    participant S as NFS Server
    participant A as API Server
    
    U->>A: 1. Create a PVC (specifying the StorageClass)
    P->>A: 2. Watch for new PVCs
    P->>S: 3. Create a unique directory on the NFS server
    P->>A: 4. Create a PV containing the created path information
    A->>A: 5. Bind the PVC to the PV (status: Bound)
    U->>A: 6. Mount the PVC in a Pod and use it
  

3. Verifying the Installation

1. Check the provisioner status: Use the kubectl get pods -n nfs command to verify that the provisioner Pod is Running.
2. Create a PVC: Apply the test test-claim.yaml.
3. Verify the binding: It is successful when the kubectl get pvc result shows the Bound status.
4. Physical verification: Check that a directory named like default-test-claim-pvc-xxx has been created in the shared directory on the NFS server.

4. Summary

With the NFS Subdir External Provisioner, users do not need to create PVs manually; simply creating a PVC automatically allocates a subdirectory on the NFS server, which greatly improves operational efficiency.