I am encountering an issue with starting a server for non-default users in JupyterHub.
When attempting to start a server for a user named “mahdi” (or any other non-default user), I receive the following error message in the JupyterHub container logs:
[I 2023-09-20 07:40:15.461 JupyterHub provider:659] Creating oauth client jupyterhub-user-mahdi
[I 2023-09-20 07:40:15.474 JupyterHub spawner:1689] Spawning jupyterhub-singleuser
[E 2023-09-20 07:40:15.479 JupyterHub user:884] Unhandled error starting mahdi's server: Exception occurred in preexec_fn.
Traceback (most recent call last):
File "/opt/conda/lib/python3.10/site-packages/jupyterhub/user.py", line 798, in spawn
url = await gen.with_timeout(timedelta(seconds=spawner.start_timeout), f)
File "/opt/conda/lib/python3.10/site-packages/jupyterhub/spawner.py", line 1699, in start
self.proc = Popen(cmd, **popen_kwargs)
File "/opt/conda/lib/python3.10/subprocess.py", line 971, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/opt/conda/lib/python3.10/subprocess.py", line 1864, in _execute_child
raise child_exception_type(err_msg)
subprocess.SubprocessError: Exception occurred in preexec_fn.
[E 2023-09-20 07:40:15.492 JupyterHub pages:313] Error starting server mahdi: Exception occurred in preexec_fn.
Traceback (most recent call last):
NoneType: None
[W 2023-09-20 07:40:15.492 JupyterHub web:1852] 500 GET /hub/spawn/mahdi (::ffff:172.17.0.1): Unhandled error starting server mahdi
[E 2023-09-20 07:40:15.493 JupyterHub log:183] {
"X-Forwarded-Host": "127.0.0.1:8000",
"X-Forwarded-Proto": "http",
"X-Forwarded-Port": "8000",
"X-Forwarded-For": "::ffff:172.17.0.1",
"Sec-Fetch-User": "?1",
"Sec-Fetch-Site": "same-origin",
"Sec-Fetch-Mode": "navigate",
"Sec-Fetch-Dest": "document",
"Upgrade-Insecure-Requests": "1",
"Cookie": "jupyterhub-hub-login=[secret]; _xsrf=[secret]; username-127-0-0-1-8888=[secret]; oauthenticator-state=[secret]; jupyterhub-session-id=[secret]",
"Connection": "close",
"Referer": "http://127.0.0.1:8000/hub/admin",
"Accept-Encoding": "gzip, deflate, br",
"Accept-Language": "en-US,en;q=0.5",
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
"User-Agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0",
"Host": "127.0.0.1:8000"
}
[E 2023-09-20 07:40:15.493 JupyterHub log:191] 500 GET /hub/spawn/mahdi (jovyan@::ffff:172.17.0.1) 60.88ms
Furthermore, when I access the URL http://127.0.0.1:8000/hub/spawn/mahdi, I receive a “500 Internal Server Error” with the message “Unhandled error starting server mahdi. You can try restarting your server from the home page.”
It is worth noting that I am able to start a notebook server successfully for the default user “jovyan” (${NB_USER}), but I encounter this issue when attempting to start a server for users such as “mahdi”, “mehran”, or “dainal”.
Here is the Dockerfile I am using for reference:
# Use an official JupyterLab 3.6.3 image as parent image
FROM jupyter/scipy-notebook:lab-3.6.3
# Copy requirements.txt and install Python dependencies
COPY --chown=${NB_UID}:${NB_GID} requirements.txt /tmp/
RUN pip install --quiet --no-cache-dir --requirement /tmp/requirements.txt && \
fix-permissions "${CONDA_DIR}" && \
fix-permissions "/home/${NB_USER}"
# Install JupyterLab extensions
RUN pip install jupyterlab-git==0.42.0 && \
pip install jupyterlab_sql
# Install passlib
RUN pip install passlib
# Install firstuseauthenticator
RUN pip install jupyterhub-firstuseauthenticator
# Copy your .env file into the working directory
COPY --chown=${NB_UID}:${NB_GID} env /home/${NB_USER}
# Load environment variables and clone your Git repository
RUN export $(grep -v '^#' env | xargs) && \
git clone https://${GIT_USER}:${GIT_TOKEN}@gitlab.scialb.fr/inria/organization/data/jupyterlab-reports.git
# Generate a new JupyterHub configuration file and set default URL to '/lab'
RUN jupyterhub --generate-config && \
sed -i "s/#c.Spawner.default_url = ''/c.Spawner.default_url = '\/lab'/" jupyterhub_config.py
# Define users and their roles
RUN echo "users = {'allowed': ['mehran', 'danial'], 'admin': ['mahdi', 'jovyan']}" >> jupyterhub_config.py # Define the users and their roles
# Set the JupyterHub admin user to mahdi and set a hashed password
RUN echo "from passlib.hash import sha256_crypt; print(sha256_crypt.hash('jupyter'))" | python3 > hashed_password.txt && \
echo "c.Authenticator.admin_users = set(users['admin'])" >> jupyterhub_config.py # Set the admin users
# Set the authenticator class and create users setting
RUN echo "c.JupyterHub.authenticator_class = 'firstuseauthenticator.FirstUseAuthenticator'" >> jupyterhub_config.py && \
echo "c.FirstUseAuthenticator.create_users = True" >> jupyterhub_config.py # Set the authenticator class and allow new users to create an account on their first login
# Set the whitelist, blacklist, and open signup settings
RUN echo "c.Authenticator.whitelist = set(users['allowed'])" >> jupyterhub_config.py # Set the whitelist of users who are allowed to log in
RUN echo "c.Authenticator.open_signup = False" >> jupyterhub_config.py # Disable open signup, meaning that new users cannot create an account without admin approval
# Switch to root user
USER root
# Add system users
RUN adduser --disabled-password --gecos "" mahdi && \
adduser --disabled-password --gecos "" danial && \
adduser --disabled-password --gecos "" mehran
# Change ownership and permissions of home directories
RUN chown -R mahdi:mahdi /home/mahdi && chmod -R 755 /home/mahdi
RUN chown -R mehran:mehran /home/mehran && chmod -R 755 /home/mehran
RUN chown -R danial:danial /home/danial && chmod -R 755 /home/danial
# Add users to 'users' group
RUN usermod -a -G users mahdi
RUN usermod -a -G users mehran
RUN usermod -a -G users danial
# Switch back to non-root user
USER ${NB_USER}
Note that each user in JupyterHub has a corresponding system user account on the machine.
(base) jovyan@203736ba2dda:~$ awk -F'[/:]' '{if ($3 >= 1000 && $3 != 65534) print $1}' /etc/passwd
jovyan
mahdi
danial
mehran
(base) jovyan@203736ba2dda:~$ id mahdi
uid=1001(mahdi) gid=1000(mahdi) groups=1000(mahdi),100(users)
(base) jovyan@203736ba2dda:~$ cd ..
(base) jovyan@203736ba2dda:/home$ ls
danial jovyan mahdi mehran
(base) jovyan@203736ba2dda:/home$