Terminals and ! commands in JupyterHub not using virtualenv Python

JupyterHub
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1

Hi all,

I’m running JupyterHub 3.1.1 in a Docker container on Kubernetes. My virtual environment is located at:

/usr/src/myproject/.venv/

My goal is that when a user opens a terminal inside Jupyterhub, python points to the venv, instead of the system Python (/usr/local/bin/python). Also, when executing shell commands in notebook cells using ! ..., I want them to use the venv Python.

Currently, terminals show:

user@<pod>:~$ which python
/usr/local/bin/python

I’ve tried setting the spawner environment:

import os

venv_bin = "/usr/src/myproject/.venv/bin"
c.Spawner.environment = {
    "PATH": f"{venv_bin}:{os.environ.get('PATH', '')}",
    "VIRTUAL_ENV": "/usr/src/myproject/.venv"
}

This does not affect terminal shells or ! commands.

I’ve read about c.LocalProcessSpawner.shell_cmd and profile scripts, but I’m not sure what the best practice is in JupyterHub 3.x to ensure all terminals and ! commands default to the virtual environment Python without hardcoding it in every user shell.

Any guidance or examples would be greatly appreciated.

Thanks!

2

Can you check if your c.Spawner.environment config is having any effect? e.g. setting “TESTVARIABLE”: “TESTVALUE”? It could be that the config isn’t being loaded, or is being overridden by some later config. Check the value of $VIRTUAL_ENV and $PATH.

For the most part, I would expect your config to work, so I expect something is getting a little wonky

If you want a virtualenv to be truly fully activated, including whatever setup scripts, you’re right that c.LocalProcessSpawner.shell_cmd could be part of it. For such things, I usually use the c.Spawner.cmd approach, where you write a shell script that does activation, etc. (maybe even bash -l), then always ends with exec jupyterhub-singleuser "$@":

#!/bin/bash -l
# ^login shell means source everything in profile.d, bash_profile, etc.

# activate the project env
source /usr/src/myproject/.venv/bin/activate

# finally, 'become' jupyterhub-singleuser
exec jupyterhub-singleuser "$@"
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