Jupyter notebooks and their related iTorch notebooks seem to be popular for tutorials, e.g the Deep Learning with Torch tutorial I started today, but I hated them and avoided them – not just for the reasons on this list, but mainly because I keep my “machine learning machine” inside my university’s firewall and this has made it a pain to run “notebooks” if you’re off-site.

When I work from home, I do so via a couple ssh hops, and then copy and paste my script files into the terminal window. But these “notebook” things require a web GUI, and X11 forwarding over mutliple ssh sessions is prohibitively slow.

I didn’t want to configure a NAT system, and was considering some kind of homegrown CGI-script system (which has “security breach” written all over it), but thankfully I stumbled upon this post on Coderwall, where the process was spelled out. For my set of systems, I needed an additional layer of port-forwarding. So for me it goes like this…

1. My machine-learning computer, which we’ll call “internal”, sits inside the firewall.
   On internal, I run the Jupyter notebook…
   me@internal$ jupyter notebook --no-browser --port=8889
   or for torch, similarly,
   me@internal:~$ itorch notebook --no-browser --port=8889
   This generates a bunch of text, including a URL with a token. It’ll say…

   Copy/paste this URL into your browser when you connect for the first time, to login with a token:
   http://localhost:8889/?token=96c92fc27f102995044da89ae111914c28e51757d57bebfc

2. The server we’ll call “doorkeeper” is visible to the outside world, and so we forward its port 8889 to the one over on “internal” where the notebook is running:
   me@doorkeeper:~$ ssh -N -n -L 127.0.0.1:8889:127.0.0.1:8889 internal

3. Then on my laptop, I run a similar port-forward so the browser will connected to the port on doorkeeper:
   me@laptop:~$ ssh -N -n -L 127.0.0.1:8889:127.0.0.1:8889 doorkeeper

4. And then on my laptop, I paste the URL from the jupyter (or itorch) notebook into my web browser…
   http://localhost:8889/?token=96c92fc27f102995044da89ae111914c28e51757d57bebfc
   …and it works! The notebook comes right up, but the only lag involves sending text over ssh, as opposed to sending X11 graphics.

(incidentally, I find ‘localhost’ sometimes doesn’t resolve, which is why I use 127.0.0.1 explicitly)

Wohoo!

---

Extra: Remotely Editing Files via rmate & Sublime Text

On laptop, in Sublime Text 3: Tools > Command Pallete > Install package > rsub

On internal (server): sudo apt-get install ruby; sudo gem install rmate

Make two reverse-SHH tunnel hops from laptop to doorkeeper to internal:

1. ssh -R 52698:127.0.0.1:52698 doorkeeper

2. (on doorkeeper) ssh -R 52698:127.0.0.1:52698 internal

3. (then on internal) rmate [whatever file you want to edit]

…and suddenly, your file appears in your Sublime Text window on your laptop!

To automate this, either alias ssh to be “ssh -R 52698:127.0.0.1:52698” or modify your ~/.ssh/config file(s)