ruby shell script to backup postgres db and copy to local path

#!/usr/bin/env ruby

# backup script for postgresql databases
# connects via ssh and copies the file to a local path

@ssh_host      = ""
@ssh_user      = ""
@ssh_pass      = ""

@db_name       = ""
@db_host       = ""
@db_user       = ""
@db_pass       = ""

@local_backup_path = ""

require 'rubygems'
require 'net/ssh'
require 'net/scp'

@file           = "#{@db_name}_#{Time.now.strftime("%Y_%m.%d_%H.%M")}.sql.bz2"
@remote_file    = "/tmp/#{@file}"
@backup_command = "pg_dump --clean --no-owner --no-privileges -U#{@db_user} -h#{@db_host} #{@db_name} | bzip2 > #{@remote_file}"

Net::SSH.start(@ssh_host, @ssh_user, :password => @ssh_pass) do |ssh|
  ssh.exec!(@backup_command) { |ch, stream, out| ch.send_data "#{@db_pass}\n" if out =~ /^Password:/ }
  Net::SCP.new(ssh).download(@remote_file, "#{@local_backup_path}#{@file}")
end