From: Todd Holloway <todd@...>
Date: 2002-07-04T06:37:30+09:00
Subject: Re: ruby and 8192 bytes

thank you...that completes my first program! Now I'll go read about
why it fixed it :)

at some point I might make it more generic and not
tied to certain IPs...but for now this works great.

todd


On Thu, Jul 04, 2002 at 06:32:05AM +0900, nobu.nokada@softhome.net wrote:
> Hi,
> 
> At Thu, 4 Jul 2002 05:27:00 +0900,
> Todd Holloway wrote:
> > I have tried just using the "system" commands by themselves
> > and they seem to work just fine. I have also tried removing
> > the "system" commands and the local file is not shortened
> > to 8192 bytes. So, something is getting corrupted in between.
> 
> Put $defout.flush (or $defout.close) before "system" commands.
> 
> -- 
> Nobu Nakada

for those who care,

#!/usr/local/bin/ruby -w

# this Ruby program takes the /etc/sysconfig/iptables from "machine1"
# and creates an appropriate one for "machine2"

# adds File.["compare", "move", "safe_unlink", "o_chmod", "mv",
# "makedirs", "cp", "cmp", "mkpath", "syscopy", "rm_f",
# "copy", "install", "catname"]
require 'ftools'
#
## in-line editting w/o a backup copy
$-i  = ""
#
## Change current working
Dir.chdir("/etc/sysconfig")
#
begin
# copy iptables to iptables4machine2 and report any errors
File.copy("iptables","iptables4machine2",true)
   rescue SystemCallError
    $stderr.print "Copy failed: " + $! + "\n"
    raise
end

# Replace any command line arguments with iptables4machine2
begin
# Replace any command line arguments with iptables4machine2
ARGV.replace(['iptables4machine2'])

  while line = gets
    next if /^\s*#/ =~ line
    next if /^\s*$/ =~ line

    # perform substitution in place
    # changes "machine1" external IP address "machine2"
    line.gsub!(/10.1.0.1/,'10.1.0.2')
    # changes "machine1" internal IP address "machine2"
    line.gsub!(/192.168.1.1/,'192.168.1.2')
    print line.gsub(/-A INPUT -s 192.168.1.2 -p icmp -m state --state NEW/,
                    '-A INPUT -s 192.168.1.1 -p icmp -m state --state NEW')
    end

    rescue SystemCallError
    $stderr.print "Something failed: " + $! + "\n"
    File.delete("iptables4machine2")
    raise
end

$defout.flush

system("ssh machine2 cp /etc/sysconfig/iptables /etc/sysconfig/iptables.orig")
system("scp iptables4machine2 machine2:/etc/sysconfig/iptables")
system("ssh machine2 /etc/init.d/iptables stop")
system("ssh machine2 /etc/init.d/iptables start")



todd