Creating a link to an NFS share in K3s Kubernetes - kubernetes

Question

I'm very new to Kubernetes, and trying to get node-red running on a small cluster of raspberry pi's
I happily managed that, but noticed that once the cluster is powered down, next time I bring it up, the flows in node-red have vanished.
So, I've create a NFS share on a freenas box on my local network and can mount it from another RPI, so I know the permissions work.
However I cannot get my mount to work in a kubernetes deployment.
Any help as to where I have gone wrong please?
apiVersion: apps/v1
kind: Deployment
metadata:
name: node-red
labels:
app: node-red
spec:
replicas: 1
selector:
matchLabels:
app: node-red
template:
metadata:
labels:
app: node-red
spec:
containers:
- name: node-red
image: nodered/node-red:latest
ports:
- containerPort: 1880
name: node-red-ui
securityContext:
privileged: true
volumeMounts:
- name: node-red-data
mountPath: /data
env:
- name: NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: TZ
value: Europe/London
volumes:
- name: node-red-data
nfs:
server: 192.168.1.96
path: /mnt/Pool1/ClusterStore/nodered
The error I am getting is
error: error validating "node-red-deploy.yml": error validating data:
ValidationError(Deployment.spec.template.spec): unknown field "nfs" in io.k8s.api.core.v1.PodSpec; if
you choose to ignore these errors, turn validation off with --validate=false
New Information
I now have the following
apiVersion: v1
kind: PersistentVolume
metadata:
name: clusterstore-nodered
labels:
type: nfs
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
path: /mnt/Pool1/ClusterStore/nodered
server: 192.168.1.96
persistentVolumeReclaimPolicy: Recycle
claim.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: clusterstore-nodered-claim
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 1Gi
Now when I start the deployment it waits at pending forever and I see the following the the events for the PVC
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal WaitForFirstConsumer 5m47s (x7 over 7m3s) persistentvolume-controller waiting for first consumer to be created before binding
Normal Provisioning 119s (x5 over 5m44s) rancher.io/local-path_local-path-provisioner-58fb86bdfd-rtcls_506528ac-afd0-11ea-930d-52d0b85bb2c2 External provisioner is provisioning volume for claim "default/clusterstore-nodered-claim"
Warning ProvisioningFailed 119s (x5 over 5m44s) rancher.io/local-path_local-path-provisioner-58fb86bdfd-rtcls_506528ac-afd0-11ea-930d-52d0b85bb2c2 failed to provision volume with StorageClass "local-path": Only support ReadWriteOnce access mode
Normal ExternalProvisioning 92s (x19 over 5m44s) persistentvolume-controller
waiting for a volume to be created, either by external provisioner "rancher.io/local-path" or manually created by system administrator
I assume that this is becuase I don't have a nfs provider, in fact if I do kubectl get storageclass I only see local-path
New question, how do I a add a storageclass for NFS? A little googleing around has left me without a clue.

Answer 1

Ok, solved the issue. Kubernetes tutorials are really esoteric and missing lots of assumed steps.
My problem was down to k3s on the pi only shipping with a local-path storage provider.
I finally found a tutorial that installed an nfs client storage provider, and now my cluster works!
This was the tutorial I found the information in.

Answer 2

In the stated Tutorial there are basically these steps to fulfill:
1.
showmount -e 192.168.1.XY
to check if the share is reachable from outside the NAS
2.
helm install nfs-provisioner stable/nfs-client-provisioner --set nfs.server=192.168.1.**XY** --set nfs.path=/samplevolume/k3s --set image.repository=quay.io/external_storage/nfs-client-provisioner-arm
Whereas you replace the IP with your NFS Server and the NFS path with your specific Path on your synology (both should be visible from your showmount -e IP command
Update 23.02.2021
It seems that you have to use another Chart and Image too:
helm install nfs-subdir-external-provisioner nfs-subdir-external-provisioner/nfs-subdir-external-provisioner --set nfs.server=192.168.1.**XY** --set nfs.path=/samplevolume/k3s --set image.repository=gcr.io/k8s-staging-sig-storage/nfs-subdir-external-provisioner
kubectl get storageclass
To check if the storageclass now exists
4.
kubectl patch storageclass nfs-client -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}' && kubectl patch storageclass local-path -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'
To configure the new Storage class as "default". Replace nfs-client and local-path with what kubectl get storageclass tells
5.
kubectl get storageclass
Final check, if it's marked as "default"

Answer 3

This is a validation error pointing at the very last part of your Deployment yaml, therefore making it an invalid object. It looks like you've made a mistake with indentations. It should look more like this:
volumes:
- name: node-red-data
nfs:
server: 192.168.1.96
path: /mnt/Pool1/ClusterStore/nodered
Also, as you are new to Kubernetes, I strongly recommend getting familiar with the concepts of PersistentVolumes and its claims. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual Pod that uses the PV.
Please let me know if that helped.