What does the installer do?¶
This document details what exactly the installer does to the machine it is run on.
apt Packages installed¶
The packages python3 and python3-venv are installed from the apt repositories.
Hub environment¶
JupyterHub is run from a python3 virtual environment located in /opt/tljh/hub. It
uses the system’s installed python and is owned by root. It also contains a binary install
of traefik. This virtual environment is completely managed by TLJH.
Note
If you try to remove TLJH, revert this action using:
sudo rm -rf /opt/tljh/hub
User environment¶
By default, a mambaforge conda environment is installed in /opt/tljh/user. This contains
the notebook interface used to launch all users, and the various packages available to all
users. The environment is owned by the root user. JupyterHub admins may use
to sudo -E conda install or sudo -E pip install packages into this environment.
This conda environment is added to $PATH for all users started with JupyterHub. If you
are using ssh instead, you can activate this environment by running the following:
source /opt/tljh/user/bin/activate
This should let you run various conda and pip commands. If you run into errors like
Command 'conda' not found, try prefixing your command with:
sudo env PATH=${PATH} <command>
By default, sudo does not respect any custom environments you have activated. The env PATH=${PATH}
‘fixes’ that.
Note
If you try to remove TLJH, revert this action using:
sudo rm -rf /opt/tljh/user
tljh-config symlink¶
We create a symlink from /usr/bin/tljh-config to /opt/tljh/hub/bin/tljh-config, so users
can run sudo tljh-config <something> from their terminal. While the user environment is added
to users’ $PATH when they launch through JupyterHub, the hub environment is not. This makes it
hard to access the tljh-config command used to change most config parameters. Hence we symlink the
tljh-config command to /usr/bin, so it is directly accessible with sudo tljh-config <command>.
Note
If you try to remove TLJH, revert this action using:
sudo unlink /usr/bin/tljh-config
jupyterhub_config.d directory for custom configuration snippets¶
Any files in /opt/tljh/config/jupyterhub_config.d that end in .py and are a valid JupyterHub configuration will be loaded after any of the config options specified with tljh-config are loaded.
Note
If you try to remove TLJH, revert this action using:
sudo rm -rf /opt/tljh/config
Systemd Units¶
TLJH places 2 systemd units on your computer. They all start on system startup.
jupyterhub.service- starts the JupyterHub service.traefik.service- starts traefik proxy that manages HTTPS
In addition, each running Jupyter user gets their own systemd unit of the name jupyter-<username>.
Note
If you try to remove TLJH, revert this action using:
# stop the services
systemctl stop jupyterhub.service
systemctl stop traefik.service
systemctl stop jupyter-<username>
# disable the services
systemctl disable jupyterhub.service
systemctl disable traefik.service
# run this command for all the Jupyter users
systemctl disable jupyter-<username>
# remove the systemd unit
rm /etc/systemd/system/jupyterhub.service
rm /etc/systemd/system/traefik.service
# reset the state of all units
systemctl daemon-reload
systemctl reset-failed
State files¶
TLJH places 3 jupyterhub.service and 4 traefik.service state files in /opt/tljh/state. These files save the state of JupyterHub and Traefik services and are meant to be used and modified solely by these services.
Note
If you try to remove TLJH, revert this action using:
sudo rm -rf /opt/tljh/state
Progress page files¶
If you ran the TLJH installer with the –show-progress-page flag, then two files have been added to your system to help serving the progress page:
/var/run/index.html- the main progress page/var/run/favicon.ico- the JupyterHub icon
Note
If you try to remove TLJH, revert this action using:
sudo rm /var/run/index.html
sudo rm /var/run/favicon.ico
User groups¶
TLJH creates two user groups when installed:
jupyterhub-userscontains all users managed by this JupyterHubjupyterhub-adminscontains all users with admin rights managed by this JupyterHub.
When a new JupyterHub user logs in, a unix user is created for them. The unix user is always added
to the jupyterhub-users group. If the user is an admin, they are added to the jupyterhub-admins
group whenever they start / stop their notebook server.
If you uninstall TLJH, you should probably remove all user accounts associated with both these
user groups, and then remove the groups themselves. You might have to archive or delete the home
directories of these users under /home/.
Note
If you try to remove TLJH, in order to remove a user and its home directory, use:
sudo userdel -r <user>
Keep in mind that the files located in other parts of the file system will have to be searched for and deleted manually.
Note
To remove the user groups units:
sudo delgroup jupyterhub-users
sudo delgroup jupyterhub-admins
# remove jupyterhub-admins from the sudoers group
sudo rm /etc/sudoers.d/jupyterhub-admins
Passwordless sudo for JupyterHub admins¶
/etc/sudoers.d/jupyterhub-admins is created to provide passwordless sudo for all JupyterHub
admins. We also set it up to inherit $PATH with sudo -E, to more easily call conda,
pip, etc.
Removing TLJH¶
If trying to wipe out a fresh TLJH installation, follow the instructions on how to revert each specific modification the TLJH installer does to the system.
Note
If using a VM, the recommended way to remove TLJH is destroying the VM and start fresh.
Warning
Completely uninstalling TLJH after it has been used is a difficult task because it’s highly coupled to how the system changed after it has been used and modified by the users. Thus, we cannot provide instructions on how to proceed in this case.