Kubernetes JupyterHub Enabling Not Working

[erinfry6]

I have looked through old issues, but cannot find the solution to my problem. I have set up a Jupyter Notebook docker image that successfully installs nbextensions and the nbextensions configurator (https://github.com/Jupyter-contrib/jupyter_nbextensions_configurator). I am using this docker image to create singleuser pods in Kubernetes JupyterHub (jupyterhub/k8s-hub:0.9.0-beta.2.000.bed779e), but when users start their pods, neither one is enabled (nbextensions are not available and neither is the tab at the top).

If users manually install/enable and restart their pod they both work fine. Additionally, if I build a docker image off the Jupyter Notebook image alone, nbextensions is enabled as intended.

My singleuser dockerfile:

FROM jupyter/datascience-notebook:2343e33dec46

COPY requirements.txt requirements.txt

## install python libraries
RUN pip install --upgrade pip && \
    pip install --upgrade -r requirements.txt && \
    sleep 60 && \
    jupyter contrib nbextension install --user && \
    jupyter nbextensions_configurator enable --user && \
	jupyter nbextension enable hinterland/hinterland && \
	jupyter nbextension enable rubberband/main && \
	jupyter nbextension enable codefolding/main

requirements.txt includes

jupyter_contrib_nbextensions
jupyter_nbextensions_configurator

My .yml file for Kubernetes JupyterHub contains the following for singleuser pod:

singleuser:
  storage:
    capacity: 1Gi
    extraVolumes:
      - name: 'nfs-volume-{username}'
        nfs:
          server: ...
          path: '/'
    extraVolumeMounts:
      - name: '...-{username}'
        mountPath: /home/jovyan/shared
  nodeSelector:
    cloud.google.com/gke-nodepool: jhub-pool
  extraEnv:
    GRANT_SUDO: "yes"
  uid: 0
  cmd: null
  cpu:
    limit: 4
    guarantee: 0.05
  memory:
    limit: 4G
    guarantee: 512M

  image:
    name: gcr.io/.../singleuser-image
    tag: ...

Any ideas about how to automatically have nbextensions available to my JupyterHub users would be greatly appreciated!!!