Host specific volumes in Kubernetes manifests - kubernetes

Question

I am fairly sure this isn't possible, but I wanted to check.
I am using Kubernetes stateful sets, so my hosts get obvious hostnames.
I'd like them to provision a hostPath mount that is mapped to their hostname.
An example helm chart that I'm using might look like this:
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
name: app
namespace: '{{ .Values.name }}'
labels:
chart: '{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}'
spec:
serviceName: "app"
replicas: {{ .Values.replicaCount }}
template:
metadata:
labels:
app: app
spec:
terminationGracePeriodSeconds: 30
containers:
- name: {{ .Chart.Name }}
image: "{{ .Values.image.repository }}/{{ .Values.image.version}}"
imagePullPolicy: '{{ .Values.image.pullPolicy }}'
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
ports:
- containerPort: {{ .Values.baseport | add 80 }}
name: app
volumeMounts:
- mountPath: /NAS/$(POD_NAME)
name: store
readOnly: true
volumes:
- name: store
hostPath:
path: /NAS/$(POD_NAME)
Essentially, instead of hardcoding a volume, I'd like to have some kind of dynamic variable as the path. I don't mind using helm or the downward API for this, but ideally it would work when I scale the stateful set outwards.
Is there any way of doing this? All my docs reading seems to think it's not... :(