ganesh-k13 / ParallelizeSSH

Simple Parallel SSH module using Paramiko.

ParallelizeSSH

Simple Parallel SSH module using Paramiko.

Dependencies:

• Paramiko 2.6
• Python 3.6+

Installation:

Usage:

from Parallelize import Parallelize
hosts = {
  "IP1":{
    "uname":"Username as a string",
    "passwd":"Password as a string",
    "sshPort":OPTIONAL, Port as a number, else defaults to 22,
    "cmds":[A list of commands, format and types explained below],
    "callbacks":[Callback functions for each command, explained below]
  },
  "IP2":{
    ...
  }
}

ssh = Parallelize(hosts)
ssh.setup()
ssh.run()
ssh.close()

cmd can be:

• Either a string (str)
• Or a special Command object (explained below).

callbacks are callable objects:

• Either a simple function.
• Callable classes (call if needed).
• All callbacks are called with three predefined arguments: stdin,stdout,stderr (in no particular order)
• An example callback is show in full example below.

Things to note:

• Commands are processed in the order of the list. I.e. Command at index 0 is processed first.
• For each command, the corresponding callback must be provided at the same index.
• So for some command cmd1 at index 1 of cmds list, the callback for it should be at index 1 of callbacks list.

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

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

A full example usage is as below:

from Parallelize.Parallelize import Command
from Parallelize.Parallelize import Parallelize

def dummyCB(stdin,stdout,stderr):
    pass
    
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),"ps aux"],
        "callbacks":[lsCallback,dummyCB]
    }
}

ssh = Parallelize(hosts)
ssh.setup()
ssh.run(waitToExit=True)