jupyter-server-proxy setup doesn't work in docker

[sprig]

Hi!

Thanks for creating this. When I try to use with jupyter inside docker using these instructions, I get a 404 page. I do see that dtale is running and if use curl inside the container to access port 40000 or if I forward it in advance, the instance is running and available. Am I missing something from the proxy configuration? I believe I saw the recommendation to use that approach in docker if one cannot forward ports in advance.

The hostname on the container is configured to be the same as the actual hostname by which jupyter is available in the browser (via a reverse proxy with TLS).

Thanks in advance for the help!
versions involved:

# ipython
Python 3.12.4 (main, Jun 27 2024, 00:07:20) [GCC 12.2.0]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.26.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import dtale

In [2]: import jupyter

In [3]: import jupyter_server_proxy

In [4]: dtale.__version__
Out[4]: '3.13.1'

In [5]: jupyter.__version__
Out[5]: '1.0.0'

In [6]: jupyter_server_proxy.__version__
Out[6]: '4.3.0'

In [7]: import jupyterlab

In [8]: jupyterlab.__version__
Out[8]: '4.2.3'