This package includes WrapSpawner and ProfilesSpawner, which provide mechanisms for runtime configuration of spawners. The inspiration for their development was to allow users to select from a range of pre-defined batch job profiles, but their operation is completely generic.

1. From root directory of this repo (where setup.py is), run pip install -e .

   If you don't actually need an editable version, you can simply run:

   pip install git+https://github.com/jupyterhub/wrapspawner

2. Add lines in jupyterhub_config.py for the spawner you intend to use, e.g.

      c = get_config()
      c.JupyterHub.spawner_class = 'wrapspawner.ProfilesSpawner'

3. Depending on the spawner, additional configuration will likely be needed.

WrapSpawner provides a mechanism to wrap the interface of a JupyterHub Spawner such that the Spawner class to use for single-user servers can be chosen dynamically. Subclasses may modify the class or properties of the child Spawner at any point before start() is called (e.g. from Authenticator pre_spawn hooks or options form processing) and that state will be preserved on restart. The start/stop/poll methods are not real coroutines, but simply pass through the Futures returned by the wrapped Spawner class.

ProfilesSpawner leverages JupyterHub's Spawner "options form" feature to allow user-driven configuration of Spawner classes while permitting:

• configuration of Spawner classes that don't natively implement options_form
• administrator control of allowed configuration changes
• runtime choice of which Spawner backend to launch

Here is a screenshot of a typical dropdown menu letting the user choose between several SLURM instances:

The following configuration snippet lets the user choose between a Jupyter server running as a local process or one of two different Docker Images to run within DockerSpawner.

c.JupyterHub.spawner_class = 'wrapspawner.ProfilesSpawner'
c.Spawner.http_timeout = 120
#------------------------------------------------------------------------------
# ProfilesSpawner configuration
#------------------------------------------------------------------------------
# List of profiles to offer for selection. Signature is:
#   List(Tuple( Unicode, Unicode, Type(Spawner), Dict ))
# corresponding to profile display name, unique key, Spawner class,
# dictionary of spawner config options.
# 
# The first three values will be exposed in the input_template as {display},
# {key}, and {type}
#
 c.ProfilesSpawner.profiles = [
       ( "Host process", 'local', 'jupyterhub.spawner.LocalProcessSpawner', {'ip':'0.0.0.0'} ),
       ('Docker Python 2/3', 'systemuser', 'dockerspawner.SystemUserSpawner', dict(container_image="jupyterhub/systemuser")),
       ('Docker Python 2/3,R,Julia', 'datasciencesystemuser', 'dockerspawner.SystemUserSpawner', dict(container_image="jupyterhub/datasciencesystemuser")),
 ]

These mechanisms originated as part of the batchspawner package. The batchspawner README contains additional examples on the use of ProfilesSpawner.