SSH to machine through a middle host

In my work with my professor I have to ssh into our server and from there I ssh into each node to run our programs. I am trying to write a python program that will let me do everything that I need to do on the remote node from my local machine. The commands that I will be running on the nodes are:

• cp files from local machine to remote nodes
• run a program on each node
• retrieve files from the nodes to my local machine
• maybe make it possible to copy over a fortran program and compile it on the nodes and also to check the nodes to see if an开发者_如何学运维y programs are running.

Right now I make my input files on my local machine, scp them to the server, then I copy the files to each node and run our fluid_dynamics program on each node. I then do the reverse to get our output back to my local machine.

I was looking at paramiko but I can not figure out how I can use it to get from my local machine to the nodes because I must go through the server. local -ssh--> server -ssh--> nodes

Is there a way to do this in python or should I try something else such as: using:

os.system(ssh -t server ssh node 'command')   

or making a bash scripts on the server for each of the different commands (compile.sh, move_inputs.sh, retrieve_outputs.sh) and then just connecting to the server and running the bash scripts.

Sorry if this doesn't make sense or if it is worded badly, any help is appreciated.

Additional Info: The reason I am using python is because I want the program to be able to make the input files, send them to the nodes and retrieve the output files, and to finally generate graphs of our data. I already have some code to generate our input files and to make the graphs from the outputs.

You don't need Python to do this. Check the ProxyCommand configuration option for SSH. Here is a tutorial that explains the details.

You can do it with Paramiko:

proxy_command = 'ssh -i %s %s@%s nc %s %s' % (proxy_key, proxy_user, proxy_host, host, 22)

proxy = paramiko.ProxyCommand(proxy_command)

client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.connect(host, username=user, password=password, sock=proxy)

stdin, stdout, stderr = client.exec_command('echo HELLO')
print "Echo: %s" % (", ".join(stdout.readlines()))
client.close()

It works with SFTPClient too:

proxy_command = 'ssh -i %s %s@%s nc %s %s' % (proxy_key, proxy_user, proxy_host, host, 22)

proxy = paramiko.ProxyCommand(proxy_command)

transport = paramiko.Transport(proxy)
transport.connect(username=user, password=password)

sftp = paramiko.SFTPClient.from_transport(transport)

With a trick from my colleague, you can ssh/scp from local to nodes directly.

Edit your ~/.ssh/config:

Host *
ControlMaster auto
ControlPath ~/.ssh/master-%r@%h:%p

Host node1 node2 or node*
ProxyCommand ssh server 'nc -w 5 %h 22'

Have fun!

You can do this by creating a tunnel through your server to the node:

import os, sys, shlex
import subprocess
import paramiko

cmd = "ssh -f -N -p " + str(serverport) + " -l " + serveruser + " -L " + str(tunnelport) + ":" + nodehost + ":" + str(nodeport) + " " + serverhost
args = shlex.split(cmd)
tun = subprocess.Popen(args)
stat = tun.poll()

Once the tunnel is set up you can ftp to the nodes:

transport = paramiko.Transport(("127.0.0.1", tunnelport))
transport.connect(username=nodeusername, password=nodepw)
sftp = paramiko.SFTPClient.from_transport(transport)
sftp.put(localfile, remotefile)

Or you can connect and execute a command using paramiko.SSHClient().connect("127.0.0.1", port=port, username=user, password=pw) and paramiko.SSHClient().exec_command(command).

Then the tunnel process can be killed thus:

p = subprocess.Popen(['ps', '-A'], stdout=subprocess.PIPE)
out, err = p.communicate()
for line in out.splitlines():
    if cmd in line:
        pid = int(line.split(None, 1)[0])
        os.kill(pid, signal.SIGKILL)

Use plink root@10.112.10.1 -pw password ls -l

Download plink and copy it to your windows machine