Passwordless SSH

You may setup a SSH key to access the cluster front ends (and compute nodes) within the CCI without being prompted for a password.

Note, passwordless SSH is not supported on the landing pads.

This is a requirement for running parallel applications with using mpirun and some other frameworks that use SSH as part of their backend function.

Instructions

To setup a passwordless SSH key, perform the steps below from any node:

1. Connect to any of the landing pads via SSH with using your password
2. Run: ssh-keygen -t rsa Accept defaults, do not set password
3. Run: cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

Troubleshooting

If asked for a password after setting up keys, check the permissions of the files in your ~/.ssh directory.

Set proper permissions

`chmod 600 ~/.ssh/id_rsa`

`chmod 644 ~/.ssh/id_rsa.pub`

`chmod 644 ~/.ssh/authorized_keys`

Working example