Install Script

Shell Programming and Scripting
1

Say I want to install x on 10 different machines.

Is there a script that will do it for me install of going to each machines and doing it manually ?

2 
if you have a ssh root access to each machine
then yes
else no
fi

:wink:

3

I do have root access.

Any ideas how to write something like this ?

4

for Debian something like

#!/bin/bash
for SERVER in ip1 ip2 ip3 .... # list of ip of servers (can be hostames if recognized)
do
    ssh root@$SERVER apt-get install program1 program2 ...
done

for other distros, use the appropriate syntax in state of "apt-get install".

5

Hello ,
that would again require to manually enter the password at the prompt for all the hosts. So I would recommend using an expect script like this

# Assume $remote_server, $my_user_id, $my_password, and $my_command were read in earlier 
  # in the script.
  # Open a ssh session to a remote server, and wait for a username prompt.
  spawn ssh $remote_server
  expect "password:"
  # Send the password, and then wait for a shell prompt.
  send "$my_password\r"
  expect "%"
  # Send the prebuilt command, and then wait for another shell prompt.
  send "$my_command\r" #apt-get install xorg 
  expect "%"
  # Capture the results of the command into a variable. This can be displayed, or written to disk.
  set results $expect_out(buffer)
  # Exit the ssh session, and wait for a special end-of-file character.
  send "exit\r"
  expect eof

you can enclose the expect statement into a foreach and get to read a text file containing each host's password from some text file.
Hope this helps.
Regards.

6

Good, i'll have to learn more about expect.
But the passwords can be seen in the script and therefore it's not very secure.
I prefer (it has to be done once for each server but can then be used later) the public key authentication.
But take care: It's secure only if nobody else uses your account on your own computer.

7

Hi All

If the list of servers is small, i would suggest that you set up passwordless ssh between the servers.
and then use your script without passwords in it.

Cheers