Support configuring the user environment

[csadorf]

With the adoption of the jupyter/minimal-notebook as the base image for this stack, the user name can be controlled via the NB_USER environment variable in combination with running the container as root user.

However, this function is currently not supported in the current edge version, likely because of this documented bug that was apparently fixed in more recent versions of the Jupyter stack. We are currently forced to depend on older version due to dependency conflicts.

[danielhollas]

Just noting my observation that might be relevant to this: Trying to run the full-stack image under root currently fails with:

/usr/local/bin/start-notebook.sh: running /usr/local/bin/before-notebook.d/20_start-postgres.sh
ERROR conda.cli.main_run:execute(33): Subprocess for 'conda run ['initdb', '-D', '/home/jovyan/.postgresql']' command failed.  (See above for error)
initdb: error: cannot be run as root
Please log in (using, e.g., "su") as the (unprivileged) user that will
own the server process.

[unkcpz]

I think the problem is the NB_USER can be set only with --user root. This will break up running all the startup hooks. Because the startup hooks in before-notebook.py are all supposed to be run as the system user rather than the root.

[danielhollas]

@unkcpz yep, that's exactly right. I provided more details in #306 if you're interested.

[unkcpz]

@danielhollas thanks! that's very helpful. But there is still no proper way to do it without hacking the start.sh I guess?

[danielhollas]

Yeah, I don't think there is right now. I am okay with that since I am building my own Docker image anyway.