Setting up a course account¶

This guide walks course participants through everything needed to access a CSCS cluster for a course, from creating an account to connecting over SSH. It is a streamlined path through the more detailed account, MFA and SSH documentation, which you can follow if you run into trouble or want more background.

Check your email¶

You should have received an invitation email from CSCS that contains a link to create your account and your course username, which looks like course_XXXXX.

You will sign your key once per day

The signed SSH certificate that lets you connect to the cluster is valid for one day. You will need to sign your key again on each day of the course, but the setup steps are only done once.

Create your account¶

Open the link in your invitation email and follow the instructions to set your password. Your course username (for example course_XXXXX) is also in the invitation email — keep it handy, as you will need it when configuring SSH.

See creating an account for a full walkthrough with screenshots.

Set up multi-factor authentication¶

The first time you sign in to a CSCS web application, for example portal.cscs.ch, you are prompted to enroll in multi-factor authentication (MFA). This is required for all CSCS services.

To enroll, install a TOTP authenticator app such as Google Authenticator on your phone, then follow the on-screen instructions: scan the displayed QR code with the app and enter the 6-digit one-time password it generates to finish the setup.

See configure the authenticator for the detailed procedure.

Set up SSH access¶

Password authentication is not available for SSH. Instead you generate an SSH key on your machine and have CSCS sign it. The steps in this section only need to be done once.

Install `cscs-key`¶

cscs-key is the CSCS command-line tool for signing and managing your SSH keys. Follow the installation instructions to install it on your machine.

Prefer not to install anything?

You can manage and sign your key entirely in the browser with the web dashboard at user-account.cscs.ch. If you go this route, sign your key there instead of running cscs-key sign below.

Generate an SSH key¶

Create a new key pair:

generate an SSH key (only needed once)

ssh-keygen -t ed25519 -f ~/.ssh/cscs-key

Configure SSH¶

Add the following to your ~/.ssh/config file. Replace course_XXXXX with your course username, and replace daint with the cluster your course uses.

~/.ssh/config

Host ela
    HostName ela.cscs.ch
    User course_XXXXX
    IdentityFile ~/.ssh/cscs-key
    IdentitiesOnly yes

Host daint
    HostName daint.alps.cscs.ch
    User course_XXXXX
    IdentityFile ~/.ssh/cscs-key
    IdentitiesOnly yes
    ProxyJump ela

This routes your connection through the Ela jump host, so you can reach the cluster directly with the daint alias.

Sign your key and connect¶

Before connecting, sign your SSH key:

sign your key (repeat each day)

$ cscs-key sign

Your web browser opens — sign in with the account you created earlier to complete the process. The signed certificate is valid for one day, so run cscs-key sign again each day you want to connect.

Once your key is signed, connect to the cluster:

connect to the cluster

$ ssh daint

See the cscs-key usage documentation for more options, such as signing a key stored in a different location with the -f flag.

Getting help¶

If you get stuck, first check the documentation linked throughout this guide. If that does not resolve it, ask your course instructors. For issues beyond the course, see getting support.