Vpn assigned dns override script.

vpn_assigned_dns_overide.rb

#!/usr/bin/env ruby
require 'pty'
require 'optparse'

unless ENV['USER'].eql?("root")
  puts "Must be run as root.\nFailed."
  exit
end

options = {}

optparse = OptionParser.new do|opts|
  opts.banner = "Sets VPN assigned DNS server address from 10.1.0.252 to 10.1.0.251 on OSX."
  options[:verbose] = false
  opts.on( '-v', '--verbose', 'Output more information' ) do
    options[:verbose] = true
  end
  opts.on( '-h', '--help', 'Display this screen' ) do
    puts opts
    exit
  end
end

optparse.parse!

scutil = PTY.spawn("scutil") do |output, input, pid|
  puts "Setting..."
  Thread.abort_on_exception = true
  thread = Thread.new do
     output.each do |line|
       if line.include?("denied")
         puts "Failed."
         exit
       end
       puts line if options[:verbose]
     end
   end
  input.write("list State:/Network/Service/[^/]+/DNS\n") 
  input.write("show State:/Network/Service/com.cisco.VPN/DNS\n") 
  input.write("d.init\n") 
  input.write("get State:/Network/Service/com.cisco.VPN/DNS\n") 
  input.write("d.show\n") 
  input.write("d.add ServerAddresses * 10.1.0.251\n") 
  input.write("d.show\n") 
  input.write("set State:/Network/Service/com.cisco.VPN/DNS\n") 
  input.write("exit\n")
  puts "Done."
  thread.join(0.5)
end