Rsync over ssh tunnel - using gateway server

Question

Environment:
----------         ----------              /|             ------------
|  Work  |         | Gateway|             | |             | cluster   |
|Station |--------------------------------| |-------------|           |
|        |         |        |          Firewall A         |           |
----------         ----------             | |             ------------
                                          |/

• Users need to transfer DATA from their workstation to the cluster. (rsync / scp)
• Firewall A ONLY allows connections (ssh) from gateway & specific internal subnets
• All users have accounts on gateway server to reach cluster from outside allowed subnets

How can users use rsync / scp to transfer data from home (or outside allowed subnets) by using the gateway server as a tunnel?

For example I for remote terminals, a user must "ssh user@gateway" and then "ssh user@cluster" to receive a terminal on the cluster. If a user only performed "ssh user@cluster", the firewall would block the connection.

Thanks

Answer 1

I usually use ssh's ability to use a config file. You can store this file here:

$HOME/.ssh/config

In this file you can add stanzas like this:

Host cluster
    ProxyCommand ssh usear@gateway nc cluster %p

This will then allow you to use tools such as ssh and rsync and target a user on the cluster system from the workstation.

$ ssh user@cluster

-or-

$ rsync somefile user@cluster:~