VS Code Remote SSH

Connect to an SCF login node¶

To connect to the SCF using VS Code,  you’ll need to have installed the Remote Development extension pack (which includes the Remote SSH extension) for your local VS Code.  Then to connect to the SCF, click on the green Remote “Quick Access” status bar button labelled >< in the lower left corner:

and choose “Host”, providing one of the SCF login nodes. You can then access your SCF files from within your local VS Code instance.

Remote Development using SSH describes this workflow in more detail.

Connect to an SCF cluster node¶

1. On one of the SCF login servers, request a Slurm “allocation” using with salloc, e.g., salloc -c 4 -t 1:00:00 for one hour on four cores on the high (default) partition. The flags are the same flags one uses with srun and sbatch.

2. Modify your  ~/.ssh/config file on your local computer to include this new stanza:

       Host scf-slurm
         # This must be the cluster node that `salloc` gave you.
         HostName scf-sm20.berkeley.edu
         # This must be the login server on which you ran `salloc`.
         ProxyJump gandalf.berkeley.edu

3. Now in VS Code on your personal machine, use the remote SSH extension to connect to the host scf-slurm by clicking on the blue icon labelled ‘><’ in the lower left corner and setting “Host” to scf-slurm.

scf-run script¶

We have prepared a shell script that you could run on your Mac or Linux machine that will carry out Steps 1 and 2 above for you. You can run scf-srun, followed by your Slurm job syntax. For example:

scf-srun -c 4 -t 1:00:00

Port forwarding (e.g., for web services such as dashboards)¶

VS Code can forward ports to your local machine. This is particularly helpful if software you are using has started a web service on the SCF machine you are accessing. One example is that the Python Dask.distributed package will start a dashboard on (by default) port 8787. You can view that service in the browser on your own machine as follows.

1. Determine the port being used by the web service (e.g., port 8787).

2. If not already open, open the Panel toolbar. You can do this via Ctrl-backtick or by opening a Terminal.

3. Click on the PORTS tab in the toolbar (it will be next to the TERMINAL tab).

4. Enter the port from #1 above as the port to forward.

5. You should see a URL in the Forwarded Address column, which will be something like localhost:8787. Go to that URL in the browser on your machine (or click on the browser icon in that column).