(topic-tljh-config)= # Configuring TLJH with `tljh-config` `tljh-config` is the commandline program used to make configuration changes to TLJH. ## Running `tljh-config` You can run `tljh-config` in two ways: 1. From inside a terminal in JupyterHub while logged in as an admin user. This method is recommended. 2. 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. (tljh-set)= ## 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: ```bash sudo tljh-config set ``` where: 1. `` is a dot-separated path to the property you want to set. 2. `` 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: ```bash sudo tljh-config set auth.DummyAuthenticator.password mypassword ``` This can only set string and numerical properties, not lists. To unset a configuration property you can use the following command: ```bash sudo tljh-config unset ``` 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 `` are listed below by categories: (tljh-base-url)= ### Base URL Use `base_url` to determine the base URL used by JupyterHub. This parameter will be passed straight to `c.JupyterHub.base_url`. (tljh-set-auth)= ### 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. (tljh-set-ports)= ### Ports 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. ```bash sudo tljh-config set http.port 8080 sudo tljh-config set https.port 8443 sudo tljh-config reload proxy ``` (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). ```bash sudo tljh-config set http.address 127.0.0.1 sudo tljh-config set https.address 127.0.0.1 sudo tljh-config reload proxy ``` (tljh-set-user-lists)= ### User Lists - `users.allowed` takes in usernames to allow - `users.banned` takes in usernames to ban - `users.admin` takes in usernames to designate as admins ```bash 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 ``` (tljh-set-user-limits)= ### 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. ```bash 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.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. ```bash sudo tljh-config set limits.cpu 2 ``` (tljh-set-user-env)= ### User Environment `user_environment.default_app` Set default application users are launched into. Currently this can only be set to: `classic` and `jupyterlab`. ```bash sudo tljh-config set user_environment.default_app jupyterlab ``` (tljh-set-extra-user-groups)= ## 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: ```bash tljh-config set users.extra_user_groups.group1 user1 ``` - `tljh-config add-item`, if multiple users are to be added to the group: ```bash tljh-config add-item users.extra_user_groups.group1 user1 tljh-config add-item users.extra_user_groups.group1 user2 ``` (tljh-view-conf)= ## View current configuration To see the current configuration, you can run the following command: ```bash sudo tljh-config show ``` This will print the current configuration of your TLJH. This is very useful when asking for support! (tljh-reload-hub)= ## Reloading JupyterHub to apply configuration After modifying the configuration, you need to reload JupyterHub for it to take effect. You can do so with: ```bash sudo tljh-config reload ``` This should not affect any running users. The JupyterHub will be restarted and loaded with the new configuration. (tljh-edit-yaml)= ## 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. ```bash sudo tljh-config --help usage: tljh-config [-h] [--config-path CONFIG_PATH] {show,unset,set,add-item,remove-item,reload} ... positional arguments: {show,unset,set,add-item,remove-item,reload} show Show current configuration unset Unset a configuration property set Set a configuration property add-item Add a value to a list for a configuration property remove-item Remove a value from a list for a configuration property reload Reload a component to apply configuration change optional arguments: -h, --help show this help message and exit --config-path CONFIG_PATH Path to TLJH config.yaml file ``` ```bash sudo tljh-config remove-item --help usage: tljh-config remove-item [-h] key_path value positional arguments: key_path Dot separated path to configuration key to remove value from value Value to remove from key_path optional arguments: -h, --help show this help message and exit ```