ParallelizeSSH

Simple Parallel SSH module using Paramiko.

Dependencies:

• Paramiko 2.6
• Python 3.6+

Installation:

pip install ParallelizeSSH

Get Started:

import os
from ParallelizeSSH import SSH
 
hosts = {
    "127.0.0.1":{
        "uname":os.getenv("PSSH_UNAME"),
        "passwd":os.getenv("PSSH_PASSWD"),
        "cmds":[
            Command("ls -l")
        ]
    }
}
 
ssh = SSH(hosts)
ssh.run(waitToExit=False)
ssh.close()

An example with custom callback:

import os
import threading
from ParallelizeSSH import Command
from ParallelizeSSH import SSH 
 
def myCallback(stdin,stdout,stderr):
    print("In My Callback")
    for line in iter(lambda: stdout.readline(),""):
        print(line)
 
hosts = {
    "127.0.0.1":{
        "uname":os.getenv("PSSH_UNAME"),
        "passwd":os.getenv("PSSH_PASSWD"),
        "cmds":[
            Command("ls -l",callback=myCallback)
        ]
    }
}
 
ssh = SSH(hosts)
ssh.run(waitToExit=False)
ssh.close()

Using isThreaded for inifinitely running commands:

from ParallelizeSSH import Command
from ParallelizeSSH import SSH 
   
def lsCallback(stdin,stdout,stderr):
    for line in iter(lambda: stdout.readline(),""):
        print(line)
 
hosts = {
    "192.168.247.128":{
        "uname":"rahulrb",
        "passwd":"rahulrb",
        "cmds":[Command("ls -l",isThreaded=True,callback=lsCallback)]
    }
}
 
ssh = SSH(hosts)
ssh.run(waitToExit=False)
ssh.close()

cmd should be:

• A Command object (explained below).

Command object accepts:

• A mandatory string which is the command to be executed.
• An optional callback which is called after command is executed. (callbacks explained below). ParallelizeSSH provides a default callback which just prints stdout.
• An optional isThreaded which allows commands to executed parallely in same system.

About callback:

• It can be a simple python function or callable classes (call if needed).
• All callbacks are called with three predefined arguments: stdin,stdout,stderr (in no particular order)
• An example callback is shown in example above.

Want to pass more parameters to callback?

Use the partial module of functools library to create partially binded functions. Usage can be found here.

Things to note:

• Commands are processed in the order of the list. I.e. Command at index 0 is processed first.

ParallelizeSSH allows commands to be executed parallelly:

Warning: All parallelized commands are run at end. Use this option for commands which never end unless terminated by another program/user.

To do so, use the Command class to create your command. Then set the isThreaded argument to True. Eg:

from ParallelizeSSH import Command
parallelCmd1 = Command("./longRunningScript.sh",isThreaded=True)
parallelCmd2 = Command("./anotherLongRunningScript.sh",isThreaded=True)

hosts = {
  "IP":{
    ...
    cmds:[parallelCmd1,parallelCmd2]
  }
}