It looks like you mainly may need to change to ${NB_USER}... not 100% sure, testing it as is now. I'll report back if/when the docker build finishes. The project I linked to above uses a wrapper docker file so that the main one can build on docker hub, and then binder can launch it quickly.
It would be very cool if you could get this up and running on beta.mybinder.org...
EDIT: You could then launch the kernel at https://beta.mybinder.org/v2/gh/notablemind/jupyter-nodejs/master. It looks like your docker file is close to getting you there. Here is one that I setup for a Fortran Jupyter kernel: https://github.com/sourceryinstitute/jupyter-CAF-kernel/blob/master/prebuild/Dockerfile
It looks like you mainly may need to change to
${NB_USER}... not 100% sure, testing it as is now. I'll report back if/when the docker build finishes. The project I linked to above uses a wrapper docker file so that the main one can build on docker hub, and then binder can launch it quickly.