Add nbserverproxy doc (#144)

Add nbserverproxy doc

docs/index.rst

@@ -89,6 +89,9 @@ Once Jupyter is installed and configured, using a Jupyter notebook is done by:
 
    $ ssh -N -L 8888:x.x.x.x:8888 username@hpc_domain
 
+Now you can go to ``http://localhost:8888`` on your browser to access the
+notebook server.
+
 Viewing the Dask Dashboard
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -121,6 +124,45 @@ availaible below:
            frameborder="0" allow="autoplay; encrypted-media"
            allowfullscreen></iframe>
 
+Dask Dashboard with Jupyter
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you are using dask-jobqueue within jupyter, one user friendly solution to
+see the Dashboard is to use `nbserverproxy
+<https://github.com/jupyterhub/nbserverproxy>`_. As Dashboard http end point is
+launched inside the same node as jupyter, this is a great solution for viewing
+it without having to do SSH tunneling. You just need to install
+``nbserverproxy`` in the python env you use for launching the notebook, and
+activate it as indicated in the docs:
+
+.. code-block::
+
+   pip install nbserverproxy
+   jupyter serverextension enable --py nbserverproxy
+
+Then, once started, the Dashboard will be accessible from your notebook URL
+by just adding the path ``/proxy/8787/status``, replacing 8787 by any other
+port you use or the Dashboard is bind to if needed. Sor for example:
+
+ - ``http://localhost:8888/proxy/8787/status`` with the example above
+ - ``http://myjupyterhub.org/user/username/proxy/8787/status`` if using
+   jupyterhub
+
+Note that if using Jupyterhub, the service admin should deploy nbserverproxy
+on the environment used for starting singleuser notebook, but each user may
+have to activate the nbserverproxy extension.
+
+Finally, you may want to update the Dashboard link that is displayed in the
+notebook, shown from Cluster and Client objects. In order to do this, just
+edit dask config file, either ``~/.config/dask/jobqueue.yaml`` or
+``~/.config/dask/distributed.yaml``, and add the following:
+
+.. code-block::
+
+   distributed.dashboard.link: "/proxy/{port}/status" # for user launched notebook
+   distributed.dashboard.link: "/user/{JUPYTERHUB_USER}/proxy/{port}/status" # for jupyterhub launched notebook
+
+
 Configuration
 -------------