Switch to a JupyterHub service

[Jeremy Tuloup]

Currently the plugin relies on the JupyterHub extra_handlers to add a couple of endpoints for managing environments:

tljh-repo2docker/tljh_repo2docker/__init__.py

Lines 196 to 208 in c42f08a

 # register the handlers to manage the user images 
 c.JupyterHub.extra_handlers.extend( 
     [ 
         (r"environments", ImagesHandler), 
         (r"api/environments", BuildHandler), 
         (r"api/environments/([^/]+)/logs", LogsHandler), 
         ( 
             r"environments-static/(.*)", 
             CacheControlStaticFilesHandler, 
             {"path": os.path.join(os.path.dirname(__file__), "static")}, 
         ), 
     ] 
 ) 

However it's been deprecated in JupyterHub for a couple of releases already:

https://jupyterhub.readthedocs.io/en/stable/reference/api/app.html#jupyterhub.app.JupyterHub.extra_handlers

Actually it used to be a service before but that was changed in #19 so it would be more integrated with the default JupyterHub UI. At the time this extension point was not deprecated. For reference it was deprecated in jupyterhub/jupyterhub#4236.

This will require some design work to find a way to make it look the same as it is now, so it still feels well integrated with the JupyterHub control panel: