From: Philip Hallstrom <ruby@...>
Date: 2007-03-15T06:49:41+09:00
Subject: Re: Ruby, net-ssh, running an application on remote systems.

I don't have an answer for your specific question, but you might look into 
capistrano.  It's meant for exactly this, although it runs each request in 
parallel, not sequentially, which may or may not be a good thing for 
you...

-philip

On Thu, 15 Mar 2007, lance.sanchez@gmail.com wrote:

> ok, I have a server with a dozen systems attached to it. there are
> commands that I need to run on each system one at a time. i can
> connect to each system with the admin script, i can launch basic
> commands i can even launch the script i need to but when that script
> tries to launch the partimage application to backup the windows
> partitions (this is all being done from linux) it doesn't, i don't get
> any good errors it just dies closes the connection an moves onto the
> next system.
>
> ==admin.rb==
> #!/usr/bin/ruby
> require 'net/ssh'
> Username='root'
> Password='{plain_text_password}'
> Hosts = (101..112).collect {|x| "192.168.0.#{x}"}
> def classroom_pc(host, command)
>  Net::SSH.start( host, Username, Password) do |session|
>    session.open_channel do |channel|
>      channel.on_success do
>        puts "Connected to #{host}"
>      end
>      channel.on_close do
>        puts "Connection Closed to #{host}"
>      end
>      #channel.on_data do |ch, data|
>      #  puts "\trecieved #{data}"
>      #  puts "\tfrom #{host}"
>      #end
>
>      channel.send_request "shell", nil, true
>      channel.send_data "#{command}\n"
>      channel.send_data "exit\n"
>    end
>    session.loop
>  end
> end
> if $0 == __FILE__
>        Hosts.length.times do |i|
>                classroom_pc(Hosts[i], "/mnt/backup/partimage.rb
> save")
>        end
> end
>
>
> ==/mnt/backup/partimage.rb==
> #!/usr/bin/ruby
> Win_drive = "/dev/hda1"
> Location = "/mnt/backup/classroom/"
> File_type = "partimag.gz"
> def help_message
>        puts "Usage:"
>        puts "\tsave to save the image"
>        puts "\tload to restore an image"
>        puts "\thelp prints this message"
> end
> def hostname
>        `hostname`.chomp
> end
> def save_image
>        system("rm #{Location}#{hostname}*")
>        system("partimage -odb -f3 -z1 save #{Win_drive} \
>        #{Location}#{hostname}.#{File_type}")
> end
> def load_image
>        system("partimage -eb -f3 restore #{Win_drive} \
>        #{Location}#{hostname}.#{File_type}.000")
> end
>
> if $0 == __FILE__
>        unless ARGV.length == 1
>                help_message
>        end
>        if ARGV.length == 1
>                help_message if ARGV[0].downcase == "help"
>                save_image if ARGV[0].downcase == "save"
>                load_image if ARGV[0].downcase == "load"
>        end
> end
>
>
>