Application-Hub

Read the configuration

config_path="/usr/local/etc/jupyterhub/config.yml"

Profile list

This method provides the Application pods spawn options. It is a map with one or more Application pod definitions.

A profile is an option shown on the JupyterHub landing page and it defines what container image is used in the pod to spawn.

It also includes the CPU and RAM limits to assign to the pod to spawn.

The profile slug is the key of the selected profile.

Based on the profile slug, the contextualization may include different elements: volumes, config maps or environment variables.

from application_hub_context.app_hub_context import DefaultApplicationHubContext

namespace_prefix = "jupyter"

def custom_options_form(spawner):

    spawner.log.info("Configure profile list")

    namespace = f"{namespace_prefix}-{spawner.user.name}"

    workspace = DefaultApplicationHubContext(
        namespace=namespace,
        spawner=spawner,
        config_path=config_path,
    )

    spawner.profile_list = workspace.get_profile_list()

    return spawner._options_form_default()

Pre-spawn hook

The pre_spawn_hook is an optional hook function that can be implemented to do bootstrapping work before the spawner starts.

This hook contextualises the Application pod to spawn and:

• may mount config maps
• may mount volumes
• may set pod environment variables

def pre_spawn_hook(spawner):

    spawner.http_timeout = 600

    profile_slug = spawner.user_options.get("profile", None)

    env = os.environ["JUPYTERHUB_ENV"].lower()

    spawner.log.info(f"Using profile slug {profile_slug}")

    namespace = f"{namespace_prefix}-{spawner.user.name}"

    workspace = DefaultApplicationHubContext(
        namespace=namespace,
        spawner=spawner,
        config_path=config_path
    )

    workspace.initialise()

    profile_id = workspace.config_parser.get_profile_by_slug(slug=profile_slug).id

    default_url = workspace.config_parser.get_profile_default_url(profile_id=profile_id)

    if default_url:
        spawner.log.info(f"Setting default url to {default_url}")
        spawner.default_url = default_url

Post-stop hook

The post_stop_hook is an optional hook function that can be implemented to do work after the spawner stops.

This hook does clean-up tasks:

• may delete temporary volumes
• may delete temporary config maps

def post_stop_hook(spawner):

    namespace = f"jupyter-{spawner.user.name}"

    workspace = DefaultApplicationHubContext(
        namespace=namespace,
        spawner=spawner,
        config_path=config_path
    )
    spawner.log.info("Dispose in post stop hook")
    workspace.dispose()