Setting New Default JupyterLab Settings#

If you or other users of your hub tend to use JupyterLab as your default notebook app, then you may want to override some of the default settings for the users of your hub. You can do this by creating a file /opt/tljh/user/share/jupyter/lab/settings/overrides.json with the necessary settings.

This how-to guide will go through the necessary steps to set new defaults for all users of your TLJH by example: setting the default theme to JupyterLab Dark.

Step 1: Change your Personal Settings#

The easiest way to set new default settings for all users starts with configuring your own settings preferences to what you would like everyone else to have.

Make sure you are in the JupyterLab notebook interface, which will look something like http(s)://<YOUR-HUB-IP>/user/<YOUR_USERNAME/lab.
Go to Settings in the menu bar and select Theme -> JupyterLab Dark.

Step 2: Determine your Personal Settings Configuration#

To set JupyterLab Dark as the default theme for all users, we will need to create a json formatted file with the setting override. Now that you have changed your personal setting, you can use the JSON Settings Editor to get the relevant setting snippet to add to the overrides.json file later.

Go to Settings -> Advanced Settings Editor then select JSON Settings Editor on the right.

Scroll down and select Theme. You should see the json formatted configuration:

{
  // Theme
  // @jupyterlab/apputils-extension:themes
  // Theme manager settings.
  // *************************************

  // Theme CSS Overrides
  // Override theme CSS variables by setting key-value pairs here
  "overrides": {
    "code-font-family": null,
    "code-font-size": null,
    "content-font-family": null,
    "content-font-size1": null,
    "ui-font-family": null,
    "ui-font-size1": null
  },

  // Selected Theme
  // Application-level visual styling theme
  "theme": "JupyterLab Dark",

  // Scrollbar Theming
  // Enable/disable styling of the application scrollbars
  "theme-scrollbars": false
}

Determine the setting that you want to change. In this example it’s the theme setting of @jupyterlab/apputils-extension:theme as can be seen above.
Build your json snippet. In this case, our snippet should look like this:
```
{
  "@jupyterlab/apputils-extension:themes": {
    "theme": "JupyterLab Dark"
  }
}
```
We only want to change the Selected Theme, so we don’t need to include the other theme-related settings for CSS and the scrollbar.
Note

To apply overrides for more than one setting, separate each setting by commas. For example, if you also wanted to change the interval at which the notebook autosaves your content, you can use
```
{
  "@jupyterlab/apputils-extension:themes": {
    "theme": "JupyterLab Dark"
  },

  "@jupyterlab/docmanager-extension:plugin": {
    "autosaveInterval": 30
  }
}
```

Step 3: Apply the Overrides to the Hub#

Once you have your setting snippet created, you can add it to the overrides.json file so that it gets applied to all users.

First, create the settings directory if it doesn’t already exist:
```
sudo mkdir -p /opt/tljh/user/share/jupyter/lab/settings
```

Use nano to create and add content to the overrides.json file:

sudo nano /opt/tljh/user/share/jupyter/lab/settings/overrides.json

Copy and paste your snippet into the file and save.
Reload your configuration:
```
sudo tljh-config reload
```

The new default settings should now be set for all users in your TLJH using the JupyterLab notebook interface.