Add custom resource usage

[ctr26]

It looks like all the BinderSpawner code is kept as an extra config and plonked into the spawner ( c.JupyterHub.spawner_class = BinderSpawner). As such, you can get the entire query string from hub_login_url and the current profile_list from c.KubeSpawner.profile_list. c.KubeSpawner.profile_list[0] is then the default profile which can be switched in based on whatever you like. I'd think the easiest (safest) would be having a list of profiles baked in that the user could choose from (profile 1/2/3 with details somewhere); the simpler but more dangerous option is letting the user provide a JSON in the query string that is taken as the profile.

Example:

  
  # extraConfig:
  #     binder: |
  import os
  import sys
  import yaml
  from tornado import web
  # get cors config from values.custom.cors
  import z2jh
  cors = z2jh.get_config('custom.cors', {})
  # image & token are set via spawn options
  from kubespawner import KubeSpawner
  class BinderSpawner(KubeSpawner):
      def get_args(self):
          args = [
              '--ip=0.0.0.0',
              '--port=%i' % self.port,
              '--NotebookApp.base_url=%s' % self.server.base_url,
              '--NotebookApp.token=%s' % self.user_options['token'],
              '--NotebookApp.trust_xheaders=True',
          ]
          allow_origin = cors.get('allowOrigin')
          if allow_origin:
              args.append('--NotebookApp.allow_origin=' + allow_origin)
          return args + self.args
      def start(self):
          if 'token' not in self.user_options:
              raise web.HTTPError(400, "token required")
          if 'image' not in self.user_options:
              raise web.HTTPError(400, "image required")
          self.image = self.user_options['image']
          return super().start()
  
  hub_login_url = c.BinderHub.hub_login_url
  
  def get_json_profile_from_url(hub_login_url):
      json = hub_login_url.get_query("profile={json}")
      # self.profile_json = json
      return json
          
  c.JupyterHub.spawner_class = BinderSpawner
  default = c.KubeSpawner.profile_list[0]
  c.KubeSpawner.profile_list = [get_json_profile_from_url(hub_login_url)]