We're creating a kubernetes statefulset that is mounting a pre-existing NFS share.

Here's a trimmed down example:

apiVersion: apps/v1beta2
kind: StatefulSet
metadata: 
  name: hostname
spec:
  replicas: 1
  selector:
    matchLabels:
      app: test
  template:
    metadata:
      labels:
        app: test
    spec:
      containers:
      - name: container
        image: 4730230466298.dkr.ecr.us-east-1.amazonaws.com/container:latest
        volumeMounts:
        - name: efs
          mountPath: /efs
          readOnly: true
      volumes:
      - name: efs
        nfs:
          path: /
          server: 10.33.1.90
          readOnly: true

This works fine, and the nfs volume is correctly mounted into the container. But how can I specify the mount options on the the mount? I've tried setting the mountOptions parameter as shown here: https://kubernetes.io/docs/concepts/storage/persistent-volumes/#mount-options

on the volume and the volumeMount and it fails to validate. I don't need (or want) to create a PV or PVC because the nfs volume already exists outside of k8s and I just need to use it.

Is there anyway to specify the mount options?