Per-host Capistrano tasks

1.rb

role :web, "192.168.1.132", :internal => "10.0.0.1"
role :app, "192.168.1.133", :internal => "10.0.0.2"
role :db,  "192.168.1.132", :primary => true
role :db,  "192.168.1.134", :no_release => true, :internal => "10.0.0.3"

2.rb

all_internal_ips = Array.new
servers = find_servers_for_task(current_task) 
servers.each do |s|
  ip = s.options[:internal]
  if !ip.nil? && ip.length > 0
    all_internal_ips.push(ip) unless all_internal_ips.include?(ip)
  end
end

3.rb

servers.each do |s|
  all_internal_ips.each do |addr|
    line = "-A INPUT -s #{addr} -i eth0 -d #{s.options[:internal]} -j ACCEPT"
    run "#{try_sudo} bash -c \" echo '#{line}' >> /etc/iptables.up.rules\"", :hosts => s
  end
end