My campus only lets ssh access through a gateway server. So to access the cluster I am coding on I have to ssh to the gateway and then ssh to the machine I am working on. The connection is very slow at times and is frustrating to work on.
I would love to use something like tramp which I understand would have the buffer open on my local machine and only talk through the network when I save to disk. I am not very familiar with tramp at all and struggling to get it to work, especially through the double hop. The documentation says this is accomplished through defining proxies in tramp, but I am unable to understand the syntax.
Does anyone know how to use emacs to code through a double hop or have an alternate workaround for editing code through two ssh hops?
If you have Emacs 24.3 or later, see Joe's answer for an alternative to the configuration described below. If you'll be using this double hop more than once, it may be worth either modifying tramp-default-proxies-alist as described below, or setting tramp-save-ad-hoc-proxies to t.
If you have Emacs 23.1 or later, then the multi method is no longer supported. You can achieve the same result by configuring "proxies".
In your .emacs config file add the following:
(add-to-list 'tramp-default-proxies-alist
'("HOSTB" nil "/ssh:USERA@HOSTA:"))
Where HOSTB is the destination host behind HOSTA.
Then type /ssh:USERB@HOSTB: and emacs will prompt for the HOSTA password then the HOSTB password.