## Insecurity with direct node access

This section described how to connection between the browser on your local host (laptop) to a Jupyter service running on Comet over HTTP and demonstrates why the connection is *not* secure.

![connection over HTTP](https://github.com/sdsc-hpc-training-org/notebooks-101/blob/master/Docs/images/jupyter-notebook-http.png?raw=true)



### Log onto comet.sdsc.edu  

`ssh -Y -l <username> <system name>.sdsc.edu`

* create a test directory, or `cd` into one you have already created
* Clone the examples repository:
`git clone https://github.com/sdsc-hpc-training-org/notebook-examples.git`


### Launch a notebook on the login node:
Run the jupyter command. Be sure to set the --ip to use the hostname, which will appear in your URL :
`[mthomas@comet-14-01:~] jupyter notebook  --no-browser --ip='/bin/hostname'`

You will see output similar to below:
```
[I 08:06:32.961 NotebookApp] JupyterLab extension loaded from /home/mthomas/miniconda3/lib/python3.7/site-packages/jupyterlab
[I 08:06:32.961 NotebookApp] JupyterLab application directory is /home/mthomas/miniconda3/share/jupyter/lab
[I 08:06:33.486 NotebookApp] Serving notebooks from local directory: /home/mthomas
[I 08:06:33.487 NotebookApp] The Jupyter Notebook is running at:
[I 08:06:33.487 NotebookApp] http://comet-14-01.sdsc.edu:8888/?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b
[I 08:06:33.487 NotebookApp]  or http://127.0.0.1:8888/?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b
[I 08:06:33.487 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[C 08:06:33.494 NotebookApp]

    To access the notebook, open this file in a browser:
        file:///home/mthomas/.local/share/jupyter/runtime/nbserver-6614-open.html
    Or copy and paste one of these URLs:
        http://comet-14-01.sdsc.edu:8888/?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b
     or http://127.0.0.1:8888/?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b
[I 08:06:45.773 NotebookApp] 302 GET /?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b (76.176.117.51) 0.74ms
[E 08:06:45.925 NotebookApp] Could not open static file ''
[W 08:06:46.033 NotebookApp] 404 GET /static/components/react/react-dom.production.min.js (76.176.117.51) 7.39ms referer=http://comet-14-01.sdsc.edu:8888/tree?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b
[W 08:06:46.131 NotebookApp] 404 GET /static/components/react/react-dom.production.min.js (76.176.117.51) 1.02ms referer=http://comet-14-01.sdsc.edu:8888/tree?token=6d7a48dda7cc1635d6d08f63aa1a696008fa89d8aa84ad2b
```

Notice that the notebook URL is using HTTP, and when you connect the browser on your local sysetm to this URL, the connection will _not_ be secure. Note: it is against SDSC Comet policy to run applications on the login nodes, and any applications being run will be killed by the system admins. A better way is to run the jobs on an interactive node or on a compute node using the batch queue (see the [Comet User Guide](https://comet.sdsc.edu)), or on a compute node, which is described in the next sections.

### Obtain an interactive node:
Jobs can be run on the cluster in `batch mode` or in `interactive mode`. Batch jobs are performed remotely and without manual intervention. Interactive mode enable you to run/compile your program and environment setup on a compute node dedicated to you. To obtain an interactive node, type:
`srun --pty --nodes=1 --ntasks-per-node=24 -p compute -t 02:00:00 --wait 0 /bin/bash`
You will have to wait for your node to be allocated - which can take a few or many minutes. You will see pending messages like the ones below:

```
srun: job 24000544 queued and waiting for resources
srun: job 24000544 has been allocated resources
[mthomas@comet-18-29:~/hpctrain/python/PythonSeries]
```

You can also check the status of jobs in the queue system to get an idea of how long you may need to wait.

Launch the Jupyter Notebook application.
Note: this application will be running on a compute node, and you must keep track of the given URL:

`jupyter notebook --no-browser --ip='/bin/hostname'`

This will give you an address which has localhost in it and a token. Something
like:
`http://comet-14-0-4:8888/?token=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx`
You can then paste it into your browser. You will see a running Jupyter
notebook and a listing of the notebooks in your directory. From there everything should be working as a regular notebook.
Note: This token is your auth so don't email/send it around. It will go away when you stop the notebook.

To learn about Python, run the ```Python basics.ipynb```   notebook.
To see an example of remote visualization, run the  ```Matplotlib.ipynb```  notebook!


#### Access the node in your browser
Copy the the URL above into the browser running on your laptop.

#### Use your jupyterlab/jupyter notebook server!
Enjoy. Note that your notebook is unsecured.