Using the ruby gem net-ssh-multi to execute a sudo command on multiple servers at once
In a previous question I figured out how to start a password-authenticated ssh sessions on multiple servers to run a single command. Now I need to be able to execute a "sudo" command. The problem is, that net-ssh-multi does not allocate a pseudo terminal (pty), which sudo needs to run, resulting in the following error:
[127.0.0.1 : stderr] sudo: sorry, you must have a tty to run sudo
According to the documentation, a pseudo-terminal can be allocated with a method call to a channel object, however, the following code does not work: it generates the "no tty" error above:
require 'net/ssh'
require 'net/ssh/multi'
Net::SSH::Multi.start do |session|
# define the servers we want to use
my_ticket.servers.each do |session_server|
session.use sessi开发者_开发知识库on_server , :user => user_name , \
:password => user_pass
end
# execute commands on all servers
session.exec 'sudo ls /root' do |channel, stream, data|
if data =~ /^\[sudo\] password for user:/
channel.request_pty # <- problem must be here.
channel.send_data user_pass
end
end
# run the aggregated event loop
session.loop
end
$ ruby --version
ruby 1.8.7 (2008-08-11 patchlevel 72) [i386-cygwin]
Can you try something like this:
channel.request_pty do |c, success|
if success
command = "sudo YOUR_COMMAND"
c.exec(command) do |c, success|
# Some processing
end
end
end
In this case 'sudo' is inside.
You need to request a pty before running the command.
session.open_channel do |ch|
ch.request_pty
ch.exec "sudo ls /root"
end
Also you may remove the tty requeriment from /etc/sudoers. To do it run visudo
and comment Defaults requiretty
This is what I wound up doing, thanks to @Christian and this wonderful Pastie:
Net::SSH::Multi.start do |session|
# define the servers we want to use
my_ticket.servers.each do |session_server|
session.use session_server , :user => my_ticket.user_name , \
:password => my_ticket.user_pass
end
session.open_channel do |channel|
channel.request_pty do |c, success|
raise "could not request pty" unless success
channel.exec "sudo YOUR_COMMAND"
channel.on_data do |c_, data|
if data = /\[sudo\]/
channel.send_data(@password + "\n")
end
puts data
end
end
end
# run the aggregated event loop
session.loop
end
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