Kubernetes : Use External Storage

Configure Persistent Storage in Kubernetes Cluster. This example is based on the environment like follows. +----------------------+ +----------------------+ | [ ctrl.srv.world ] | | [ dlp.srv.world ] | | Manager Node | | Control Plane | +-----------+----------+ +-----------+----------+ eth0|10.0.0.25 eth0|10.0.0.30 | | ------------+--------------------------+----------- | | eth0|10.0.0.51 eth0|10.0.0.52 +-----------+----------+ +-----------+----------+ | [ node01.srv.world ] | | [ node02.srv.world ] | | Worker Node#1 | | Worker Node#2 | +----------------------+ +----------------------+

	For example, configure cluster that pods can use NFS share as external storage on NFS server [nfs.srv.world (10.0.0.35)].
[1]	Configure NFS Server, refer to here. On this example, set [/home/nfsshare] directory as NFS share.
[2]	Create PV (Persistent Volume) object and PVC (Persistent Volume Claim) object.

# create PV definition debian@ctrl:~$  vi nfs-pv.yml apiVersion: v1 kind: PersistentVolume metadata: # any PV name name: nfs-pv spec: capacity: # storage size storage: 10Gi accessModes: # Access Modes: # - ReadWriteMany (RW from multi nodes) # - ReadWriteOnce (RW from a node) # - ReadOnlyMany (R from multi nodes) - ReadWriteMany persistentVolumeReclaimPolicy: # retain even if pods terminate Retain nfs: # NFS server definition path: /home/nfsshare server: 10.0.0.35 readOnly: false debian@ctrl:~$  kubectl create -f nfs-pv.yml persistentvolume "nfs-pv" created debian@ctrl:~$  kubectl get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS VOLUMEATTRIBUTESCLASS REASON AGE nfs-pv 10Gi RWX Retain Available <unset> 5s # create PVC definition debian@ctrl:~$  vi nfs-pvc.yml apiVersion: v1 kind: PersistentVolumeClaim metadata: # any PVC name name: nfs-pvc spec: accessModes: - ReadWriteMany resources: requests: storage: 10Gi debian@ctrl:~$  kubectl create -f nfs-pvc.yml persistentvolumeclaim "nfs-pvc" created debian@ctrl:~$  kubectl get pvc NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS VOLUMEATTRIBUTESCLASS AGE nfs-pvc Bound nfs-pv 10Gi RWX <unset> 4s

[3]	Create Pods with PVC above.

debian@ctrl:~$  vi nginx-nfs.yml apiVersion: apps/v1 kind: Deployment metadata: # any Deployment name name: nginx-nfs labels: name: nginx-nfs spec: replicas: 3 selector: matchLabels: app: nginx-nfs template: metadata: labels: app: nginx-nfs spec: containers: - name: nginx-nfs image: nginx ports: - name: web containerPort: 80 volumeMounts: - name: nfs-share # mount point in container mountPath: /usr/share/nginx/html volumes: - name: nfs-share persistentVolumeClaim: # PVC name you created claimName: nfs-pvc debian@ctrl:~$  kubectl apply -f nginx-nfs.yml deployment.apps/nginx-nfs created debian@ctrl:~$  kubectl get pods -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-nfs-57fb56bc6b-bzqrg 1/1 Running 0 10s 192.168.40.204 node01.srv.world <none> <none> nginx-nfs-57fb56bc6b-fsgh2 1/1 Running 0 10s 192.168.241.136 node02.srv.world <none> <none> nginx-nfs-57fb56bc6b-gzrzk 1/1 Running 0 10s 192.168.40.205 node01.srv.world <none> <none> debian@ctrl:~$  kubectl expose deployment nginx-nfs --type="NodePort" --port 80 service/nginx-nfs exposed debian@ctrl:~$  kubectl port-forward service/nginx-nfs --address 127.0.0.1 8081:80 & # create a test file under the NFS share debian@ctrl:~$  kubectl exec nginx-nfs-57fb56bc6b-bzqrg -- sh -c "echo 'NFS Persistent Storage Test' > /usr/share/nginx/html/index.html" # verify access debian@ctrl:~$  curl localhost:8081 Handling connection for 8081 NFS Persistent Storage Test