Starting and accessing a Jupyter Notebook (Linux / macOS)

To run a Jupyter Notebook in the DTU databar while displaying it output in your browser requires three steps.

  • Starting the notebook on an interactive compute node.

  • Make a connection to the relevant compute node, bypassing the firewall.

  • Connecting your browser to the Jupyter Notebook process.

Logging into the databar

If you are not already logged into the databar, do so by starting a Terminal window. Log in to the databar front-end with the command:

ssh -XY USERNAME@login.gbar.dtu.dk

Replace USERNAME with your DTU username, and note that when you are asked for a password, you should use your DTU password, not the Jupyter password you just created!

Once you are logged in on the front-end, get a session on an interactive compute node by typing the command:

linuxsh -X

Starting a Jupyter Notebook

Change to the folder where you keep your notebooks (most likely CAMD2022) and start the Jupyter Notebook server:

cd CAMD2022
source venv/bin/activate
camdnotebook

The command camdnotebook is a local script. It checks that you are on a compute server (and not on the front-end) and that X11 forwarding is enabled. Then it starts a jupyter notebook by running the command jupyter notebook --no-browser --port=40000 --ip=$HOSTNAME (you can also use this command yourself if you prefer).

The Notebook server replies by printing a few status lines, as seen here

../../_images/JupyterRunningMac.png

The important line is the second from the bottom, it shows on which computer and port number the notebook is running (here n-62-27-18 and 40000, respectively).

Create an SSH Tunnel to the notebook

You now need to create an SSH tunnel to the server directly from your laptop. It is also done with an ssh command, which unfortunately is a bit cryptic. Open a new Terminal window on your laptop, and write the following command:

ssh USERNAME@login.gbar.dtu.dk -g -L8080:HOSTNAME:PORT -N

I this line, you should replace USERNAME with your DTU username, HOSTNAME with the servername you see in the other terminal window (it has the form n-XX-YY-ZZ) and PORT with the port number you see in that line (typically 40000 or close). The command will ask for a password, you need your DTU password, not the Jupyter password. There is no feedback in form of stars when you type the password. If you type the password correctly (and press enter) then the command gives no feedback indicating that it is running!

Starting a browser.

Start a browser (Chrome and Firefox are known to work well) and write in the address bar:

http://localhost:8080

Your browser is now asking for your Jupyter password (the one you created when setting up your account). You are now ready to open one of the notebooks, and run the exercises.

Logging out

When you are done for the day, please

  • Save all notebooks, then select Close and Halt on the file menu.

  • Stop the SSH tunnel.

  • Stop the Jupyter Notebook server by pressing Control-C twice in the window where it is running.

  • Log out of the databar by typing exit twice in the window(s).