i have read other Stackoverflow threads on this. Those are older posts, i would like to get the latest update.
Is it possible to send multiple commands over single channel in Paramiko ? or is it still not possible ?
If so, is there any other library which can do the same.
Example scenario, automating the Cisco router confi. : User need to first enter "Config t" before entering the other other commands. Its currently not possible in paramiko.
THanks.
if you are planning to use the exec_command() method provided within the paramiko API , you would be limited to send only a single command at a time , as soon as the command has been executed the channel is closed.
The below excerpt from Paramiko API docs .
exec_command(self, command) source code Execute a command on the server. If the server allows it, the channel will then be directly connected to the stdin, stdout, and stderr of the command being executed.
When the command finishes executing, the channel will be closed and can't be reused. You must open a new channel if you wish to execute another command.
but since transport is also a form of socket , you can send commands without using the exec_command() method, using barebone socket programming.
Incase you have a defined set of commands then both pexpect and exscript can be used , where you read a set of commands form a file and send them across the channel.
See my answer here or this page
import threading, paramiko
strdata=''
fulldata=''
class ssh:
shell = None
client = None
transport = None
def __init__(self, address, username, password):
print("Connecting to server on ip", str(address) + ".")
self.client = paramiko.client.SSHClient()
self.client.set_missing_host_key_policy(paramiko.client.AutoAddPolicy())
self.client.connect(address, username=username, password=password, look_for_keys=False)
self.transport = paramiko.Transport((address, 22))
self.transport.connect(username=username, password=password)
thread = threading.Thread(target=self.process)
thread.daemon = True
thread.start()
def closeConnection(self):
if(self.client != None):
self.client.close()
self.transport.close()
def openShell(self):
self.shell = self.client.invoke_shell()
def sendShell(self, command):
if(self.shell):
self.shell.send(command + "\n")
else:
print("Shell not opened.")
def process(self):
global strdata, fulldata
while True:
# Print data when available
if self.shell is not None and self.shell.recv_ready():
alldata = self.shell.recv(1024)
while self.shell.recv_ready():
alldata += self.shell.recv(1024)
strdata = strdata + str(alldata)
fulldata = fulldata + str(alldata)
strdata = self.print_lines(strdata) # print all received data except last line
def print_lines(self, data):
last_line = data
if '\n' in data:
lines = data.splitlines()
for i in range(0, len(lines)-1):
print(lines[i])
last_line = lines[len(lines) - 1]
if data.endswith('\n'):
print(last_line)
last_line = ''
return last_line
sshUsername = "SSH USERNAME"
sshPassword = "SSH PASSWORD"
sshServer = "SSH SERVER ADDRESS"
connection = ssh(sshServer, sshUsername, sshPassword)
connection.openShell()
connection.send_shell('cmd1')
connection.send_shell('cmd2')
connection.send_shell('cmd3')
time.sleep(10)
print(strdata) # print the last line of received data
print('==========================')
print(fulldata) # This contains the complete data received.
print('==========================')
connection.close_connection()
Have a look at parallel-ssh:
from pssh.pssh2_client import ParallelSSHClient
cmds = ['my cmd1', 'my cmd2']
hosts = ['myhost']
client = ParallelSSHClient(hosts)
for cmd in cmds:
output = client.run_command(cmd)
# Wait for completion
client.join(output)
Single client, multiple commands over same SSH session and optionally multiple hosts in parallel - also non-blocking.
I find this simple to understand and use. Code provides 2 examples with singlehost and multihost. Also added example where you can login to a second user and continue your commands with that user.
More info can be found in here: https://parallel-ssh.readthedocs.io/en/latest/advanced.html?highlight=channel#interactive-shells
from pssh.clients import SSHClient
from pssh.exceptions import Timeout
from pssh.clients import ParallelSSHClient
from pssh.config import HostConfig
def singleHost():
host_ = "10.3.0.10"
pwd_ = "<pwd>"
pwd_root = "<root pwd>"
user_ = "<user>"
client = SSHClient(host_, user=user_, password=pwd_, timeout=4, num_retries=1)
#####
shell = client.open_shell(read_timeout=2)
shell.run("whoami")
# login as new user example
shell.run("su - root")
shell.stdin.write(pwd_root + "\n")
shell.stdin.flush()
shell.run("pwd")
try:
# Reading Partial Shell Output, with 'timeout' > client.open_shell(read_timeout=2)
for line in shell.stdout:
print(line)
except Timeout:
pass
shell.run("whoami")
shell.run("cd ..")
print(".......")
try:
# Reading Partial Shell Output, with 'timeout' > client.open_shell(read_timeout=2)
for line in shell.stdout:
print(line)
except Timeout:
pass
shell.close()
def multiHost():
pwd_ = "<pwd>"
user_ = "<user>"
workingIP_list = ["10.3.0.10", "10.3.0.10"]
host_config_ = []
# HostConfig is needed one per each 'workingIP_list'
host_config_.append(HostConfig(user=user_, password=pwd_))
host_config_.append(HostConfig(user=user_, password=pwd_))
client_ = ParallelSSHClient(workingIP_list, host_config=host_config_, num_retries=1, timeout=3)
# now you have an open shell
shells = client_.open_shell(read_timeout=2)
command = "pwd"
client_.run_shell_commands(shells, command)
try:
# Reading Partial Shell Output, with 'timeout' > client_.open_shell(read_timeout=2)
for line in shells[0].stdout:
print(line)
except Timeout:
pass
print(".......")
command = "cd repo/"
client_.run_shell_commands(shells, command)
command = "pwd"
client_.run_shell_commands(shells, command)
#Joined on shells are closed and may not run any further commands.
client_.join_shells(shells)
for shell in shells:
for line in shell.stdout:
print(line)
print(shell.exit_code)
if __name__ == '__main__':
print("singleHost example:")
singleHost()
print("multiHost example:")
multiHost()
