Nested SSH using Python Paramiko

Question

I have this scenario:

Local-host --------- jump-host ------- target-machine

I am trying to write a code in Python using Paramiko to first SSH from local-host to jump-host and then SSH from jump-host to the target-machine. From the target-machine, I want to capture some outputs and store them locally either as a variable or as a file (haven't got to that point yet). I found an example from Stack Overflow where they talk about using nested SSH with Paramiko, and I follow it but I get stuck here:

My code:

enter code here

#!/usr/bin/python
#
# Paramiko
#
import paramiko
import sys
import subprocess
#
# we instantiate a new object referencing paramiko's SSHClient class
#
vm=paramiko.SSHClient()
vm.set_missing_host_key_policy(paramiko.AutoAddPolicy())
vm.connect('192.168.115.103',username='osmanl',password='xxxxxx')
#
vmtransport = vm.get_transport()
dest_addr = ('192.168.115.103', 22)
local_addr = ('127.0.0.1', 22)
vmchannel = vmtransport.open_channel("direct-tcpip", dest_addr, local_addr)
#
jhost=paramiko.SSHClient()
jhost.set_missing_host_key_policy(paramiko.AutoAddPolicy())
jhost.load_host_keys('/home/osmanl/.ssh/known_hosts')
jhost.connect('10.103.53.26', username='latiu', password='xxxx', sock=vmchannel)
#
stdin, stdout, stderr = rtr.exec_command("show version | no-more")
#
print stdout.readline()
#
jhost.close()
vm.close()
# End

---

When I run the above, I get this error:

$ python sshvm.py
Traceback (most recent call last):
  File "sshvm.py", line 28, in <module>
    jhost.load_host_keys('/home/osmanl/.ssh/known_hosts')
  File "/usr/lib/python2.7/site-packages/paramiko-1.15.2-py2.7.egg/paramiko/client.py", line 121, in load_host_keys
    self._host_keys.load(filename)
  File "/usr/lib/python2.7/site-packages/paramiko-1.15.2-py2.7.egg/paramiko/hostkeys.py", line 94, in load
    with open(filename, 'r') as f:
IOError: [Errno 2] No such file or directory: '/home/osmanl/.ssh/known_hosts'

Answer 1

Try the following edited code, it should work:

#!/usr/bin/python
#
# Paramiko
#
import paramiko
import sys
import subprocess
#
# we instantiate a new object referencing paramiko's SSHClient class
#
vm = paramiko.SSHClient()
vm.set_missing_host_key_policy(paramiko.AutoAddPolicy())
vm.connect('192.168.115.103', username='osmanl', password='xxxxxx')
#
vmtransport = vm.get_transport()
dest_addr = ('10.103.53.26', 22) #edited#
local_addr = ('192.168.115.103', 22) #edited#
vmchannel = vmtransport.open_channel("direct-tcpip", dest_addr, local_addr)
#
jhost = paramiko.SSHClient()
jhost.set_missing_host_key_policy(paramiko.AutoAddPolicy())
#jhost.load_host_keys('/home/osmanl/.ssh/known_hosts') #disabled#
jhost.connect('10.103.53.26', username='latiu', password='xxxx', sock=vmchannel)
#
stdin, stdout, stderr = jhost.exec_command("show version | no-more") #edited#
#
print stdout.read() #edited#
#
jhost.close()
vm.close()
# End

Answer 2

I know OP has specifically asked for Paramiko but i can do this very easily with fabric. Here is my solution

from fabric import Connection

out = Connection('host1').run('host2 uptime')
print(out.stdout.strip())

This works just fine for me, and i have the output stored in a variable as well.