So I built a program that prints out the login logs of my ubuntu server using tail -f.
The program uses Paramiko to connect via ssh and runs the command to tail the logs.
The program works but it prints out the motd from the server which is unnecessary.
I've tried splicing using itertools.
Tried using next().
Still doesn't work.
Here's my code:
import yaml, paramiko, getpass, traceback, time, itertools
from paramiko_expect import SSHClientInteraction
with open("config.yaml", "r") as yamlfile:
cfg = yaml.load(yamlfile, Loader=yaml.FullLoader)
def main():
command = "sudo tail -f /var/log/auth.log"
try:
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
server_pw = getpass.getpass("Enter the password for your account %s on %s:" % (cfg['ssh_config']['username'], cfg['ssh_config']['host']))
sudo_pw = getpass.getpass("Enter the sudo password for %s on %s: " % (cfg['ssh_config']['username'], cfg['ssh_config']['host']))
ssh.connect(hostname = cfg['ssh_config']['host'], username = cfg['ssh_config']['username'], port = cfg['ssh_config']['port'], password = server_pw)
interact = SSHClientInteraction(ssh, timeout=10, display=False)
interact.send(command)
interact.send(sudo_pw + "\n")
with open(interact.tail(line_prefix=cfg['ssh_config']['servername']+': ')) as tail:
for line in itertools.islice(tail, 17, None):
print(line)
except KeyboardInterrupt:
print('Ctrl+C interruption detected, stopping tail')
except Exception:
traceback.print_exc()
finally:
try:
ssh.close()
except:
pass
if __name__ == '__main__':
main()
You get MOTD because you are opening an interactive shell session. I do not think you need that, quite on the contrary.
Use SSHClient.exec_command instead:
stdin, stdout, stderr = ssh.exec_command(command, get_pty=True)
stdin.write(sudo_pw + "\n")
stdin.flush()
for line in iter(stdout.readline, ""):
print(line, end="")
Related questions:
Get output from a Paramiko SSH exec_command continuously
Pass input/variables to command/script over SSH using Python Paramiko
What is the difference between exec_command and send with invoke_shell() on Paramiko?
Obligatory warning: Do not use AutoAddPolicy – You are losing a protection against MITM attacks by doing so. For a correct solution, see Paramiko "Unknown Server".
Just using my first paramiko script, we have an opengear console server, so I'm trying to automate setup of any device we plug into it.
The open gear listens for ssh connections on ports, for example a device in port 1 would be 3001. I am connecting to a device on port 8, which works and my script runs, but for some reason, after I get the "Interactive SSH session established" message, I need to hit return on the session to make it run (so I have a ssh session and the script does too, its shared).
It just waits there until I hit return, I've tried sending returns as you can see but they don't work, only a manual return works, which is odd because technically they are the same thing?
import paramiko
import time
def disable_paging(remote_conn):
'''Disable paging on a Cisco router'''
remote_conn.send("terminal length 0\n")
time.sleep(1)
# Clear the buffer on the screen
output = remote_conn.recv(1000)
return output
if __name__ == '__main__':
# VARIABLES THAT NEED CHANGED
ip = '192.168.1.10'
username = 'root'
password = 'XXXXXX'
port = 3008
# Create instance of SSHClient object
remote_conn_pre = paramiko.SSHClient()
# Automatically add untrusted hosts (make sure okay for security policy in your environment)
remote_conn_pre.set_missing_host_key_policy(
paramiko.AutoAddPolicy())
# initiate SSH connection
remote_conn_pre.connect(ip, username=username, password=password,port=port, look_for_keys=False, allow_agent=False)
print "SSH connection established to %s" % ip
# Use invoke_shell to establish an 'interactive session'
remote_conn = remote_conn_pre.invoke_shell()
print "Interactive SSH session established"
time.sleep(1)
remote_conn.send("\n")
# Strip the initial router prompt
#output = remote_conn.recv(1000)
# See what we have
#print output
# Turn off paging
#disable_paging(remote_conn)
# clear any config sessions
is_global = remote_conn.recv(1024)
if ")#" in is_global:
remote_conn.send("end\n")
time.sleep(2)
# if not in enable mode go to enable mode
is_enable = remote_conn.recv(1024)
if ">" in is_enable:
remote_conn.send("enable\n")
time.sleep(1)
remote_conn.send("conf t\n")
remote_conn.send("int g0/0/1\n")
remote_conn.send("ip address 192.168.1.21 255.255.255.0\n")
remote_conn.send("no shut\n")
remote_conn.send("end\n")
# Wait for the command to complete
time.sleep(2)
remote_conn.send("ping 192.168.1.1\n")
time.sleep(1)
output = remote_conn.recv(5000)
print output
I tried this and saw that
is_global = remote_conn.recv(1024)
hangs,
Are you sure '192.168.1.10' sends somthing to be received ?
Try setting a timeout
remote_conn.settimeout(3)
3 seconds for example, do it after this line:
remote_conn = remote_conn_pre.invoke_shell()
this way the recv func does not hang and continues when timeout expires
works for me
first send some command "ls -ltr\n" and then call sleep
remote_conn.send("ls -ltr\n")
time.sleep(1)
Try running your command in a debugger and find out what line is waiting for input. You might also try sending \r or \r\n instead if just \n. Remember the enter key is really ^M
You might also try turning on detailed logging.
import logging
# ...
logging.getLogger("paramiko").setLevel(logging.DEBUG)
ive found another module (netmiko) which does exactly what i want and does all these checks. ive since abandoned trying to do it myself when someone else has already done it better.
use Netmiko! :)
I'm writing some pexpect stuff that's basically sending commands over telnet.
But, it's possible that my telnet session could die (due to networking problems, a cable getting pulled, whatnot).
How do I initialize a telnet session such that, if it dies, I can catch it and tell it to reconnect and then continue execution of the code where it was at.
Is this possible?
IMHO, you're normally better-off with a currently-maintained library like exscript or telnetlib, but the efficient incantation in pexpect is:
import pexpect as px
cmds = ['cmd1', 'cmd2', 'cmd3']
retcode = -1
while (retcode<10):
if (retcode<2):
child = px.spawn('telnet %s %s' % (ip_addr,port))
lregex = '(sername:)' # Insert regex for login prompt here
pregex = '(prompt1>)|(prompt2$)' # Insert your prompt regex here
# retcode = 0 for px.TIMEOUT, 1 for px.EOF, 2 for lregex match...
retcode = child.expect([px.TIMEOUT, px.EOF, lregex, pregex],timeout = 10)
if (retcode==2):
do_login(child) # Build a do_login() method to send user / passwd
elif (2<retcode<10) and (len(cmds)>0):
cmd = cmds.pop(0)
child.sendline(cmd)
else:
retcode = 10
I did this, and it worked:
def telnet_connect():
print "Trying to connect via telnet..."
telnet_connecting = pexpect.spawn('telnet localhost 10023', timeout=2)
while 1:
try:
telnet_connecting.expect('login: ')
break
except:
telnet_connecting = telnet_connect()
break
return telnet_connecting
Recursion FTW?
I'm writing a script to automate some command line commands in Python. At the moment, I'm doing calls like this:
cmd = "some unix command"
retcode = subprocess.call(cmd,shell=True)
However, I need to run some commands on a remote machine. Manually, I would log in using ssh and then run the commands. How would I automate this in Python? I need to log in with a (known) password to the remote machine, so I can't just use cmd = ssh user#remotehost, I'm wondering if there's a module I should be using?
I will refer you to paramiko
see this question
ssh = paramiko.SSHClient()
ssh.connect(server, username=username, password=password)
ssh_stdin, ssh_stdout, ssh_stderr = ssh.exec_command(cmd_to_execute)
If you are using ssh keys, do:
k = paramiko.RSAKey.from_private_key_file(keyfilename)
# OR k = paramiko.DSSKey.from_private_key_file(keyfilename)
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(hostname=host, username=user, pkey=k)
Keep it simple. No libraries required.
import subprocess
# Python 2
subprocess.Popen("ssh {user}#{host} {cmd}".format(user=user, host=host, cmd='ls -l'), shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
# Python 3
subprocess.Popen(f"ssh {user}#{host} {cmd}", shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
Or you can just use commands.getstatusoutput:
commands.getstatusoutput("ssh machine 1 'your script'")
I used it extensively and it works great.
In Python 2.6+, use subprocess.check_output.
I found paramiko to be a bit too low-level, and Fabric not especially well-suited to being used as a library, so I put together my own library called spur that uses paramiko to implement a slightly nicer interface:
import spur
shell = spur.SshShell(hostname="localhost", username="bob", password="password1")
result = shell.run(["echo", "-n", "hello"])
print result.output # prints hello
If you need to run inside a shell:
shell.run(["sh", "-c", "echo -n hello"])
All have already stated (recommended) using paramiko and I am just sharing a python code (API one may say) that will allow you to execute multiple commands in one go.
to execute commands on different node use : Commands().run_cmd(host_ip, list_of_commands)
You will see one TODO, which I have kept to stop the execution if any of the commands fails to execute, I don't know how to do it. please share your knowledge
#!/usr/bin/python
import os
import sys
import select
import paramiko
import time
class Commands:
def __init__(self, retry_time=0):
self.retry_time = retry_time
pass
def run_cmd(self, host_ip, cmd_list):
i = 0
while True:
# print("Trying to connect to %s (%i/%i)" % (self.host, i, self.retry_time))
try:
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(host_ip)
break
except paramiko.AuthenticationException:
print("Authentication failed when connecting to %s" % host_ip)
sys.exit(1)
except:
print("Could not SSH to %s, waiting for it to start" % host_ip)
i += 1
time.sleep(2)
# If we could not connect within time limit
if i >= self.retry_time:
print("Could not connect to %s. Giving up" % host_ip)
sys.exit(1)
# After connection is successful
# Send the command
for command in cmd_list:
# print command
print "> " + command
# execute commands
stdin, stdout, stderr = ssh.exec_command(command)
# TODO() : if an error is thrown, stop further rules and revert back changes
# Wait for the command to terminate
while not stdout.channel.exit_status_ready():
# Only print data if there is data to read in the channel
if stdout.channel.recv_ready():
rl, wl, xl = select.select([ stdout.channel ], [ ], [ ], 0.0)
if len(rl) > 0:
tmp = stdout.channel.recv(1024)
output = tmp.decode()
print output
# Close SSH connection
ssh.close()
return
def main(args=None):
if args is None:
print "arguments expected"
else:
# args = {'<ip_address>', <list_of_commands>}
mytest = Commands()
mytest.run_cmd(host_ip=args[0], cmd_list=args[1])
return
if __name__ == "__main__":
main(sys.argv[1:])
paramiko finally worked for me after adding additional line, which is really important one (line 3):
import paramiko
p = paramiko.SSHClient()
p.set_missing_host_key_policy(paramiko.AutoAddPolicy()) # This script doesn't work for me unless this line is added!
p.connect("server", port=22, username="username", password="password")
stdin, stdout, stderr = p.exec_command("your command")
opt = stdout.readlines()
opt = "".join(opt)
print(opt)
Make sure that paramiko package is installed.
Original source of the solution: Source
The accepted answer didn't work for me, here's what I used instead:
import paramiko
import os
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
# ssh.load_system_host_keys()
ssh.load_host_keys(os.path.expanduser('~/.ssh/known_hosts'))
ssh.connect("d.d.d.d", username="user", password="pass", port=22222)
ssh_stdin, ssh_stdout, ssh_stderr = ssh.exec_command("ls -alrt")
exit_code = ssh_stdout.channel.recv_exit_status() # handles async exit error
for line in ssh_stdout:
print(line.strip())
total 44
-rw-r--r--. 1 root root 129 Dec 28 2013 .tcshrc
-rw-r--r--. 1 root root 100 Dec 28 2013 .cshrc
-rw-r--r--. 1 root root 176 Dec 28 2013 .bashrc
...
Alternatively, you can use sshpass:
import subprocess
cmd = """ sshpass -p "myPas$" ssh user#d.d.d.d -p 22222 'my command; exit' """
print( subprocess.getoutput(cmd) )
References:
https://github.com/onyxfish/relay/issues/11
https://stackoverflow.com/a/61016663/797495
Notes:
Just make sure to connect manually at least one time to the remote system via ssh (ssh root#ip) and accept the public key, this is many times the reason from not being able connect using paramiko or other automated ssh scripts.
I have used paramiko a bunch (nice) and pxssh (also nice). I would recommend either. They work a little differently but have a relatively large overlap in usage.
First: I'm surprised that no one has mentioned fabric yet.
Second: For exactly those requirements you describe I've implemented an own python module named jk_simpleexec. It's purpose: Making running commands easy.
Let me explain a little bit about it for you.
The 'executing a command locally' problem
My python module jk_simpleexec provides a function named runCmd(..) that can execute a shell (!) command locally or remotely. This is very simple. Here is an example for local execution of a command:
import jk_simpleexec
cmdResult = jk_simpleexec.runCmd(None, "cd / ; ls -la")
NOTE: Be aware that the returned data is trimmed automatically by default to remove excessive empty lines from STDOUT and STDERR. (Of course this behavior can be deactivated, but for the purpose you've in mind exactly that behavior is what you will want.)
The 'processing the result' problem
What you will receive is an object that contains the return code, STDOUT and STDERR. Therefore it's very easy to process the result.
And this is what you want to do as the command you execute might exist and is launched but might fail in doing what it is intended to do. In the most simple case where you're not interested in STDOUT and STDERR your code will likely look something like this:
cmdResult.raiseExceptionOnError("Something went wrong!", bDumpStatusOnError=True)
For debugging purposes you want to output the result to STDOUT at some time, so for this you can do just this:
cmdResult.dump()
If you would want to process STDOUT it's simple as well. Example:
for line in cmdResult.stdOutLines:
print(line)
The 'executing a command remotely' problem
Now of course we might want to execute this command remotely on another system. For this we can use the same function runCmd(..) in exactly the same way but we need to specify a fabric connection object first. This can be done like this:
from fabric import Connection
REMOTE_HOST = "myhost"
REMOTE_PORT = 22
REMOTE_LOGIN = "mylogin"
REMOTE_PASSWORD = "mypwd"
c = Connection(host=REMOTE_HOST, user=REMOTE_LOGIN, port=REMOTE_PORT, connect_kwargs={"password": REMOTE_PASSWORD})
cmdResult = jk_simpleexec.runCmd(c, "cd / ; ls -la")
# ... process the result stored in cmdResult ...
c.close()
Everything remains exactly the same, but this time we run this command on another host. This is intended: I wanted to have a uniform API where there are no modifications required in the software if you at some time decide to move from the local host to another host.
The password input problem
Now of course there is the password problem. This has been mentioned above by some users: We might want to ask the user executing this python code for a password.
For this problem I have created an own module quite some time ago. jk_pwdinput. The difference to regular password input is that jk_pwdinput will output some stars instead of just printing nothing. So for every password character you type you will see a star. This way it's more easy for you to enter a password.
Here is the code:
import jk_pwdinput
# ... define other 'constants' such as REMOTE_LOGIN, REMOTE_HOST ...
REMOTE_PASSWORD = jk_pwdinput.readpwd("Password for " + REMOTE_LOGIN + "#" + REMOTE_HOST + ": ")
(For completeness: If readpwd(..) returned None the user canceled the password input with Ctrl+C. In a real world scenario you might want to act on this appropriately.)
Full example
Here is a full example:
import jk_simpleexec
import jk_pwdinput
from fabric import Connection
REMOTE_HOST = "myhost"
REMOTE_PORT = 22
REMOTE_LOGIN = "mylogin"
REMOTE_PASSWORD = jk_pwdinput.readpwd("Password for " + REMOTE_LOGIN + "#" + REMOTE_HOST + ": ")
c = Connection(host=REMOTE_HOST, user=REMOTE_LOGIN, port=REMOTE_PORT, connect_kwargs={"password": REMOTE_PASSWORD})
cmdResult = jk_simpleexec.runCmd(
c = c,
command = "cd / ; ls -la"
)
cmdResult.raiseExceptionOnError("Something went wrong!", bDumpStatusOnError=True)
c.close()
Final notes
So we have the full set:
Executing a command,
executing that command remotely via the same API,
creating the connection in an easy and secure way with password input.
The code above solves the problem quite well for me (and hopefully for you as well). And everything is open source: Fabric is BSD-2-Clause, and my own modules are provided under Apache-2.
Modules used:
fabric : http://www.fabfile.org/
jk_pwdinput : https://github.com/jkpubsrc/python-module-jk-pwdinput
jk_simplexec : https://github.com/jkpubsrc/python-module-jk-simpleexec
Happy coding! ;-)
Works Perfectly...
import paramiko
import time
ssh = paramiko.SSHClient()
#ssh.load_system_host_keys()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('10.106.104.24', port=22, username='admin', password='')
time.sleep(5)
print('connected')
stdin, stdout, stderr = ssh.exec_command(" ")
def execute():
stdin.write('xcommand SystemUnit Boot Action: Restart\n')
print('success')
execute()
You can use any of these commands, this will help you to give a password also.
cmd = subprocess.run(["sshpass -p 'password' ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null root#domain.com ps | grep minicom"], shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
print(cmd.stdout)
OR
cmd = subprocess.getoutput("sshpass -p 'password' ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null root#domain.com ps | grep minicom")
print(cmd)
Have a look at spurplus, a wrapper we developed around spur that provides type annotations and some minor gimmicks (reconnecting SFTP, md5 etc.): https://pypi.org/project/spurplus/
Asking User to enter the command as per the device they are logging in.
The below code is validated by PEP8online.com.
import paramiko
import xlrd
import time
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
loc = ('/Users/harshgow/Documents/PYTHON_WORK/labcred.xlsx')
wo = xlrd.open_workbook(loc)
sheet = wo.sheet_by_index(0)
Host = sheet.cell_value(0, 1)
Port = int(sheet.cell_value(3, 1))
User = sheet.cell_value(1, 1)
Pass = sheet.cell_value(2, 1)
def details(Host, Port, User, Pass):
time.sleep(2)
ssh.connect(Host, Port, User, Pass)
print('connected to ip ', Host)
stdin, stdout, stderr = ssh.exec_command("")
x = input('Enter the command:')
stdin.write(x)
stdin.write('\n')
print('success')
details(Host, Port, User, Pass)
#Reading the Host,username,password,port from excel file
import paramiko
import xlrd
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
loc = ('/Users/harshgow/Documents/PYTHON_WORK/labcred.xlsx')
wo = xlrd.open_workbook(loc)
sheet = wo.sheet_by_index(0)
Host = sheet.cell_value(0,1)
Port = int(sheet.cell_value(3,1))
User = sheet.cell_value(1,1)
Pass = sheet.cell_value(2,1)
def details(Host,Port,User,Pass):
ssh.connect(Host, Port, User, Pass)
print('connected to ip ',Host)
stdin, stdout, stderr = ssh.exec_command("")
stdin.write('xcommand SystemUnit Boot Action: Restart\n')
print('success')
details(Host,Port,User,Pass)
The most modern approach is probably to use fabric. This module allows you to set up an SSH connection and then run commands and get their results over the connection object.
Here's a simple example:
from fabric import Connection
with Connection("your_hostname") as connection:
result = connection.run("uname -s", hide=True)
msg = "Ran {0.command!r} on {0.connection.host}, got stdout:\n{0.stdout}"
print(msg.format(result))
I wrote a simple class to run commands on remote over native ssh, using the subprocess module:
Usage
from ssh_utils import SshClient
client = SshClient(user='username', remote='remote_host', key='path/to/key.pem')
# run a list of commands
client.cmd(['mkdir ~/testdir', 'ls -la', 'echo done!'])
# copy files/dirs
client.scp('my_file.txt', '~/testdir')
Class source code
https://gist.github.com/mamaj/a7b378a5c969e3e32a9e4f9bceb0c5eb
import subprocess
from pathlib import Path
from typing import Union
class SshClient():
""" Perform commands and copy files on ssh using subprocess
and native ssh client (OpenSSH).
"""
def __init__(self,
user: str,
remote: str,
key_path: Union[str, Path]) -> None:
"""
Args:
user (str): username for the remote
remote (str): remote host IP/DNS
key_path (str or pathlib.Path): path to .pem file
"""
self.user = user
self.remote = remote
self.key_path = str(key_path)
def cmd(self,
cmds: list[str],
strict_host_key_checking=False) -> None:
"""runs commands consecutively, ensuring success of each
after calling the next command.
Args:
cmds (list[str]): list of commands to run.
strict_host_key_checking (bool, optional): Defaults to True.
"""
strict_host_key_checking = 'yes' if strict_host_key_checking \
else 'no'
cmd = ' && '.join(cmds)
subprocess.run(
[
'ssh',
'-i', self.key_path,
'-o', f'StrictHostKeyChecking={strict_host_key_checking}',
'-o', 'UserKnownHostsFile=/dev/null',
f'{self.user}#{self.remote}',
cmd
]
)
def scp(self, source: Union[str, Path], destination: Union[str, Path]):
"""Copies `srouce` file to remote `destination` using the
native `scp` command.
Args:
source (Union[str, Path]): Source file path.
destination (Union[str, Path]): Destination path on remote.
"""
subprocess.run(
[
'scp',
'-i', self.key_path,
str(source),
f'{self.user}#{self.remote}:{str(destination)}',
]
)
Below example, incase if you want user inputs for hostname,username,password and port no.
import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
def details():
Host = input("Enter the Hostname: ")
Port = input("Enter the Port: ")
User = input("Enter the Username: ")
Pass = input("Enter the Password: ")
ssh.connect(Host, Port, User, Pass, timeout=2)
print('connected')
stdin, stdout, stderr = ssh.exec_command("")
stdin.write('xcommand SystemUnit Boot Action: Restart\n')
print('success')
details()