Setting config options for jupyter-proxy-server via jupyterhub

I’d like to pass in options to set the jupyter server proxy stuff for each container launched by Jupyterhub.

Basically I’m trying to get it to pass in something like:

c.ServerProxy.servers = {
  'openrefine': {
    'command': ['refine', '-p', '{port}']

Ideally I’d like to do this via the hub config. Is this doable? Or would you recommend that I bake this into the in the singleuser container ?

OK - it looks like it is really up to the spawner to pass in the flags in question, and I think this probably belongs in the notebook config.