tljh-config is the commandline program used to make configuration changes to TLJH. Running tljh-config # You can run tljh-config in two ways: From inside a terminal in JupyterHub while logged in as an admin user. This method is recommended. From inside a terminal in JupyterHub while logged in as an admin user. This method is recommended. By directly calling /opt/tljh/hub/bin/tljh-config as root when logged in to the server via other means (such as SSH). This is an advanced use case, and not covered much in this guide. By directly calling /opt/tljh/hub/bin/tljh-config as root when logged in to the server via other means (such as SSH). This is an advanced use case, and not covered much in this guide. Set / Unset a configuration property # TLJH’s configuration is organized in a nested tree structure. You can set a particular property with the following command: <property-path> is a dot-separated path to the property you want to set. <property-path> is a dot-separated path to the property you want to set. <value> is the value you want to set the property to. <value> is the value you want to set the property to. For example, to set the password for the DummyAuthenticator, you need to set the auth.DummyAuthenticator.password property. You would do so with the following: This can only set string and numerical properties, not lists. To unset a configuration property you can use the following command: Unsetting a configuration property removes the property from the configuration file. If what you want is only to change the property’s value, you should use set and overwrite it with the desired value. Some of the existing <property-path> are listed below by categories: Use base_url to determine the base URL used by JupyterHub. This parameter will be passed straight to c.JupyterHub.base_url . Authentication # Use auth.type to determine authenticator to use. All parameters in the config under auth.{auth.type} will be passed straight to the authenticators themselves. Use http.port and https.port to set the ports that TLJH will listen on, which are 80 and 443 by default. However, if you change these, note that TLJH does a lot of other things to the system (with user accounts and sudo rules primarily) that might break security assumptions your other applications have, so use with extreme caution. (tljh-set-listen-address) Listen address # Use http.address and https.address to set the addresses that TLJH will listen on, which is an empty address by default (it means it listens on all interfaces by default). users.allowed takes in usernames to allow users.allowed takes in usernames to allow users.banned takes in usernames to ban

users.banned takes in usernames to ban users.admin takes in usernames to designate as admins sudo tljh-config add-item users.allowed good-user_1 sudo tljh-config add-item users.allowed good-user_2 sudo tljh-config add-item users.banned bad-user_6 sudo tljh-config add-item users.admin admin-user_0 sudo tljh-config remove-item users.allowed good-user_2 users.admin takes in usernames to designate as admins User Server Limits # limits.memory Specifies the maximum memory that can be used by each individual user. By default there is no memory limit. The limit can be specified as an absolute byte value. You can use the suffixes K, M, G or T to mean Kilobyte, Megabyte, Gigabyte or Terabyte respectively. Setting it to None disables memory limits. sudo tljh-config set limits.memory 4G Even if you want individual users to use as much memory as possible, it is still good practice to set a memory limit of 80-90% of total physical memory. This prevents one user from being able to single handedly take down the machine accidentally by OOMing it. limits.memory Specifies the maximum memory that can be used by each individual user. By default there is no memory limit. The limit can be specified as an absolute byte value. You can use the suffixes K, M, G or T to mean Kilobyte, Megabyte, Gigabyte or Terabyte respectively. Setting it to None disables memory limits. Even if you want individual users to use as much memory as possible, it is still good practice to set a memory limit of 80-90% of total physical memory. This prevents one user from being able to single handedly take down the machine accidentally by OOMing it. limits.cpu A float representing the total CPU-cores each user can use. By default there is no CPU limit. 1 represents one full CPU, 4 represents 4 full CPUs, 0.5 represents half of one CPU, etc. This value is ultimately converted to a percentage and rounded down to the nearest integer percentage, i.e. 1.5 is converted to 150%, 0.125 is converted to 12%, etc. Setting it to None disables CPU limits. sudo tljh-config set limits.cpu 2 limits.cpu A float representing the total CPU-cores each user can use. By default there is no CPU limit. 1 represents one full CPU, 4 represents 4 full CPUs, 0.5 represents half of one CPU, etc. This value is ultimately converted to a percentage and rounded down to the nearest integer percentage, i.e. 1.5 is converted to 150%, 0.125 is converted to 12%, etc. Setting it to None disables CPU limits. User Environment # user_environment.default_app Set default application users are launched into. Currently this can only be set to: classic and jupyterlab . Extra User Groups # users.extra_user_groups is a configuration option that can be used to automatically add a user to a specific group. By default, there are no extra groups defined. Users can be “paired” with the desired, existing groups using: tljh-config set , if only one user is to be added to the desired group: tljh-config set , if only one user is to be added to the desired group: tljh-config add-item , if multiple users are to be added to the group: tljh-config add-item , if multiple users are to be added to the group: View current configuration # To see the current configuration, you can run the following command: This will print the current configuration of your TLJH. This is very useful when asking for support! Reloading JupyterHub to apply configuration # After modifying the configuration, you need to reload JupyterHub for it to take effect. You can do so with: This should not affect any running users. The JupyterHub will be restarted and loaded with the new configuration. Advanced: config.yaml # tljh-config is a simple program that modifies the contents of the config.yaml file located at /opt/tljh/config/config.yaml . tljh-config is the recommended method of editing / viewing configuration since editing YAML by hand in a terminal text editor is a large source of errors. To learn more about the tljh-config usage, you can use the --help flag. The --help flag can be used either directly, to get information about the general usage of the command or after a positional argument. For example, using it after an argument like remove-item gives information about this specific command.