Re: [INTERFACES] documentation for ssh tunnelling of connections?

Eric Marsden wrote:

> Can anyone point me to some documentation describing how to set up ssh
> to tunnell TCP/IP connections to a backend? My searches have found several
> people saying it is possible, but no step-by-step explanation I could
> point people to.

Eric,

It's the documentation for SSH that you are looking for. Please refer to
http://www.heimhardt.de/htdocs/ssh.html for better insight.

A step-by-step explanation can be done in just two steps:

1. Establish a tunnel to the backend machine, like this:

ssh -L 3333:wit.mcs.anl.gov:5432 postgres(at)wit(dot)mcs(dot)anl(dot)gov

The first number in the -L argument, 3333, is the port number of
your end of the tunnel. The second number, 5432, is the remote
end of the tunnel -- the port number your backend is using. The
name or the address in between the port numbers belongs to the
server machine, as does the last argument to ssh that also includes
the optional user name. Without the user name, ssh will try the
name you are currently logged on as on the client machine. You can
use any user name the server machine will accept, not necessarily
those related to postgres.

2. Now that you have a running ssh session, you can connect a
postgres client to your local host at the port number you
specified in step 1. If it's psql, you will need another shell
because the shell session you used in step 1 is now
occupied with ssh.

psql -h localhost -p 3333 -d mpw

Note that you have to specify the -h argument to cause your client to
use the TCP socket instead of the Unix socket. You can omit the port
argument if you chose 5432 as your end of the tunnel.

--Gene