# Customizing User Environment¶

This page contains instructions for common ways to enhance the user experience. For a list of all the configurable Helm chart options, see the Configuration Reference.

The user environment is the set of software packages, environment variables, and various files that are present when the user logs into JupyterHub. The user may also see different tools that provide interfaces to perform specialized tasks, such as JupyterLab, RStudio, RISE and others.

A Docker image built from a Dockerfile will lay the foundation for the environment that you will provide for the users. The image will for example determine what Linux software (curl, vim …), programming languages (Julia, Python, R, …) and development environments (JupyterLab, RStudio, …) are made available for use.

To get started customizing the user environment, see the topics below.

## Choose and use an existing Docker image¶

Project Jupyter maintains the jupyter/docker-stacks repository, which contains ready to use Docker images. Each image includes a set of commonly used science and data science libraries and tools. They also provide excellent documentation on how to choose a suitable image.

If you wish to use another image from jupyter/docker-stacks than the base-notebook used by default, such as the datascience-notebook image containing useful tools and libraries for datascience, complete these steps:

1. Modify your config.yaml file to specify the image. For example:

singleuser:
image:
# Get the latest image tag at:
# https://hub.docker.com/r/jupyter/datascience-notebook/tags/
# Inspect the Dockerfile at:
# https://github.com/jupyter/docker-stacks/tree/master/datascience-notebook/Dockerfile
name: jupyter/datascience-notebook
tag: 177037d09156


Note

Container image names cannot be longer than 63 characters.

Always use an explicit tag, such as a specific commit. Avoid using latest as it might cause a several minute delay, confusion, or failures for users when a new version of the image is released.

2. Apply the changes by following the directions listed in apply the changes.

Note

If you have configured prePuller.hook.enabled, all the nodes in your cluster will pull the image before the the hub is upgraded to let users use the image. The image pulling may take several minutes to complete, depending on the size of the image.

Note

If you’d like users to select an environment from multiple docker images, see multiple-profiles.

## Use JupyterLab by default¶

JupyterLab is a new user interface for Jupyter about to replace the classic user interface (UI). While users already can interchange /tree and /lab in the URL to switch between the classic UI and JupyterLab, they will default to use the classic UI.

To let users use JupyterLab by default, add the following entries to your config.yaml:

singleuser:
defaultUrl: "/lab"

hub:
extraConfig: |-
c.Spawner.cmd = ['jupyter-labhub']


Note

All images in the jupyter/docker-stacks repository come pre-installed with JupyterLab and the JupyterLab-Hub extension required for this configuration to work.

## Customize an existing Docker image¶

If you are missing something in the image that you would like all users to have, we recommend that you build a new image on top of an existing Docker image from jupyter/docker-stacks.

Below is an example Dockerfile building on top of the minimal-notebook image. This file can be built to a docker image, and pushed to a image registry, and finally configured in config.yaml to be used by the Helm chart.

FROM jupyter/minimal-notebook:177037d09156
# Get the latest image tag at:
# https://hub.docker.com/r/jupyter/minimal-notebook/tags/
# Inspect the Dockerfile at:
# https://github.com/jupyter/docker-stacks/tree/master/minimal-notebook/Dockerfile

RUN pip install --yes astropy


## Set environment variables¶

One way to affect your user’s environment is by setting environment variables. While you can set them up in your Docker image if you build it yourself, it is often easier to configure your Helm chart through values provided in your config.yaml.

To set this up, edit your config.yaml and apply the changes. For example, this code snippet will set the environment variable EDITOR to the value vim:

singleuser:
extraEnv:
EDITOR: "vim"


You can set any number of static environment variables in the config.yaml file.

Users can read the environment variables in their code in various ways. In Python, for example, the following code reads an environment variable’s value:

import os
my_value = os.environ["MY_ENVIRONMENT_VARIABLE"]


It is important to understand the basics of how user storage is set up. By default, each user will get 10GB of space on a harddrive that will persist in between restarts of their server. This harddrive will be mounted to their home directory. In practice this means that everything a user writes to the home directory (/home/jovyan) will remain, and everything else will be reset in between server restarts.

A server can be shut down by culling. By default, JupyterHub’s culling service is configured to cull a users server that has been inactive for one hour. Note that JupyterLab will autosave files, and as long as the file was within the users home directory no work is lost.

Note

In Kubernetes, a PersistantVolume (PV) represents the harddrive. KubeSpawner will create a PersistantVolumeClaim that requests a PV from the cloud. By default, deleting the PVC will cause the cloud to delete the PV.

Docker image’s $HOME directory will be hidden from the user. To make these contents visible to the user, you must pre-populate the user’s filesystem. To do so, you would include commands in the config.yaml that would be run each time a user starts their server. The following pattern can be used in config.yaml: singleuser: lifecycleHooks: postStart: exec: command: ["cp", "-a", "src", "target"]  Each element of the command needs to be a separate item in the list. Note that this command will be run from the $HOME location of the user’s running container, meaning that commands that place files relative to ./ will result in users seeing those files in their home directory. You can use commands like wget to place files where you like.

However, keep in mind that this command will be run each time a user starts their server. For this reason, we recommend using nbgitpuller to synchronize your user folders with a git repository.

### Using nbgitpuller to synchronize a folder¶

We recommend using the tool nbgitpuller to synchronize a folder in your user’s filesystem with a git repository whenever a user starts their server. This synchronization can also be triggered by letting a user visit a link like https://your-domain.com/hub/user-redirect/git-pull?repo=https://github.com/data-8/materials-fa18 (e.g., as alternative start url).

To use nbgitpuller, first make sure that you install it in your Docker image. Once this is done, you’ll have access to the nbgitpuller CLI from within JupyterHub. You can run it with a postStart hook with the following configuration

singleuser:
lifecycleHooks:
postStart:
exec:
command: ["gitpuller", "https://github.com/data-8/materials-fa17", "master", "materials-fa"]


This will synchronize the master branch of the repository to a folder called $HOME/materials-fa each time a user logs in. See the nbgitpuller documentation for more information on using this tool. Warning nbgitpuller will attempt to automatically resolve merge conflicts if your user’s repository has changed since the last sync. You should familiarize yourself with the nbgitpuller merging behavior prior to using the tool in production. ### Allow users to create their own conda environments¶ Sometimes you want users to be able to create their own conda environments. By default, any environments created in a JupyterHub session will not persist across sessions. To resolve this, take the following steps: 1. Ensure the nb_conda_kernels package is installed in the root environment (e.g., see Build a Docker image with repo2docker) 2. Configure Anaconda to install user environments to a folder within $HOME.

Create a file called .condarc in the home folder for all users, and make sure that the following lines are inside:

envs_dirs:
- /home/jovyan/my-conda-envs/

The text above will cause Anaconda to install new environments to this folder, which will persist across sessions.

### Using multiple profiles to let users select their environment¶

You can create configurations for multiple user environments, and let users select from them once they log in to your JupyterHub. This is done by creating multiple profiles, each of which is attached to a set of configuration options that override your JupyterHub’s default configuration (specified in your Helm Chart). This can be used to let users choose among many Docker images, to select the hardware on which they want their jobs to run, or to configure default interfaces such as Jupyter Lab vs. RStudio.

Each configuration is a set of options for Kubespawner, which defines how Kubernetes should launch a new user server pod. Any configuration options passed to the profileList configuration will overwrite the defaults in Kubespawner (or any configuration you’ve added elsewhere in your helm chart).

Profiles are stored under singluser.profileList, and are defined as a list of profiles with specific configuration options each. Here’s an example:

singleuser:
profileList:
- display_name: "Name to be displayed to users"
description: "Longer description for users."
# Configuration unique to this profile
kubespawner_override:
# Defines the default profile - only use for one profile
default: true


The above configuration will show a screen with information about this profile displayed when users start a new server.

Here’s an example with two profiles that lets users select the environment they wish to use.

singleuser:
# Defines the default image
image:
name: jupyter/minimal-notebook
tag: 2343e33dec46
profileList:
- display_name: "Minimal environment"
description: "To avoid too much bells and whistles: Python."
default: true
- display_name: "Datascience environment"
description: "If you want the additional bells and whistles: Python, R, and Julia."
kubespawner_override:
image: jupyter/datascience-notebook:2343e33dec46
- display_name: "Spark environment"
description: "The Jupyter Stacks spark image!"
kubespawner_override:
image: jupyter/all-spark-notebook:2343e33dec46


This allows users to select from three profiles, each with their own environment (defined by each Docker image in the configuration above).

Note

You can also control the HTML used for the profile selection page by using the Kubespawner profile_form_template configuration. See the Kubespawner configuration reference for more information.