Jupyter notebook server extension to proxy web services. This enables users to reach arbitrary web services running within their spawned Jupyter server and is probably most appropriate for services which can't readily be converted into extensions.
A user starts a web service via New > Terminal:
echo "hello world" > index.html
python -m http.server 8001
The service is proxied off of /proxy/ at https://address.of.notebook.server/user/theuser/proxy/8001.
Install via Conda:
conda install -c conda-forge nbserverproxy
or
Install from git repo:
pip install git+https://github.com/jupyterhub/nbserverproxy
jupyter serverextension enable --py nbserverproxy
Based on https://github.com/senko/tornado-proxy.