Problem originating SSH tunnels from python

Question

The object is to set up n number of ssh tunnels between satellite servers and a centralized registry database. I have already set up public key authentication between my servers

Answer 1

Here is a cutdown version of the script that Alex pointed you to.

It simply connects to 192.168.0.8 and forwards port 3389 from 192.168.0.6 to localhost

import select
import SocketServer
import sys
import paramiko

class ForwardServer(SocketServer.ThreadingTCPServer):
    daemon_threads = True
    allow_reuse_address = True

class Handler (SocketServer.BaseRequestHandler):
    def handle(self):
        try:
            chan = self.ssh_transport.open_channel('direct-tcpip', (self.chain_host, self.chain_port), self.request.getpeername())
        except Exception, e:
            print('Incoming request to %s:%d failed: %s' % (self.chain_host, self.chain_port, repr(e)))
            return
        if chan is None:
            print('Incoming request to %s:%d was rejected by the SSH server.' % (self.chain_host, self.chain_port))
            return

        print('Connected!  Tunnel open %r -> %r -> %r' % (self.request.getpeername(), chan.getpeername(), (self.chain_host, self.chain_port)))
        while True:
            r, w, x = select.select([self.request, chan], [], [])
            if self.request in r:
                data = self.request.recv(1024)
                if len(data) == 0:
                    break
                chan.send(data)
            if chan in r:
                data = chan.recv(1024)
                if len(data) == 0:
                    break
                self.request.send(data)
        chan.close()
        self.request.close()
        print('Tunnel closed from %r' % (self.request.getpeername(),))

def main():
    client = paramiko.SSHClient()
    client.load_system_host_keys()
    client.set_missing_host_key_policy(paramiko.WarningPolicy())
    client.connect("192.168.0.8")

    class SubHandler(Handler):
        chain_host = "192.168.0.6"
        chain_port = 3389
        ssh_transport = client.get_transport()

    try:
        ForwardServer(('', 3389), SubHandler).serve_forever()
    except KeyboardInterrupt:
        sys.exit(0)

if __name__ == '__main__':
    main()

Answer 2

Is there a special reason not to just do it with ssh, the usual

(ssh -L <localport>:localhost:<remoteport> <remotehost>)

minuet? Anyway, this script is an example of local port forwarding (AKA tunneling).