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Socket Proxy

There are a number of browser-based applications such as R Studio Server for R or Jupyter Server for Jupyter Notebook that could be launched directly from the compute nodes. To access these applications, we have traditionally used X11-forwarding, meaning to launch an instance of Firefox from inside the compute node and display it on the local computer. This approach is typically slow.

In this guide, we will look at how to setup a socket connection with Palmetto to enable access to internal web applications inside Palmetto directly on local browser programs. While this requires a slightly more elaborate setup than X-forwarding, it is also faster and more convenient to use.

Currently, this guide is designed for Firefox browser. Additional information on Chrome, Edge, and Safari will be added.

  • Notation: USERNAME means your Palmetto login name.

Setup socket proxy access on MacOS/Linux​

  • Setup the SSH tunnel with port forwarding to Palmetto. Open a terminal and run the following command (this terminal must be kept opened for the socket proxy to be active):
ssh -D 8080 -C -q -N USERNAME@login.palmetto.clemson.edu

Screenshot of a Mac/Linux terminal that is prompting the user for two-factor authentication.

Setup socket proxy access on Windows​

  • On the menu button bar of MobaXterm, click Tunneling

Screenshot of the MobaXterm menu bar with the tunneling option circled.

  • Select New SSH tunnel, then select Dynamic port forwarding (SOCKS proxy)
  • Filling the information as follows:
    • <Forwarded port>: 8080
    • <SSH server>: login.palmetto.clemson.edu
    • <SSH login>: USERNAME
    • <SSH port>: 22
  • Click Save

Screenshot of the MobaXterm tunnelling configuration page.

  • Click the play icon to activate the tunnel.

Screenshot of the MobaSSHTunnel graphical port forwarding tool.

  • You will first be asked for password, that is your Palmetto password.
  • Next, you will be asked for a Duo two-factor login, enter 1 to receive a DUO push to your phone.
  • The play icon will be blurred, and the stop icon will become bolded. Your tunnel is now activated. You can click on the X at the top right corner to close this windows, and the tunnel will keep running.

Screenshot of the MobaSSHTunnel graphical port forwarding tool with the play icon blurred.

Enable Firefox to view website through the proxy​

  • This is similar across all
  • Download and install Firefox if you don't already have it.
  • Setup Firefox:
    • Select Firefox then Preferences.
    • Scroll to the bottom of General and click the Settings button in the Network Settings section.
    • Select Manual Proxy configuration and fill in localhost for SOCKS Host and 8080 for Port.
    • Check SOCKS v5.
    • Check Proxy DNS when using SOCKS v5.
    • Check Enable DNS over HTTPS.
    • Make sure everything else is unchecked, then click OK.

Screenshot of the Firefox connection settings.

  • If Firefox is your primary browser, you will need to reverse the process and change back to the default Use system proxy settings in your Firefox' Preferences/General/Network Settings after you are done.

Test proxy​

  • Login to Palmetto, then get a computer node and launch a Jupyter notebook server.
ssh USERNAME@login.palmetto.clemson.edu
qsub -I
module load anaconda3/2022.10-gcc/9.5.0
jupyter notebook --ip=0.0.0.0 --no-browser

If you are on a Windows machine, use MobaXterm to login to Palmetto as normal.

Screenshot of a Mac/Linux terminal logging in to the Palmetto.

  • Open the browser that has proxy setup and copy the entire notebook link (the one with nodeXXXX.palmetto.clemson.edu extension) into the URL bar.
  • Your notebook server should show up, and you can start working as normal.

Screenshot of a Jupyter Notebook example.