Open multiple SSH tunnels to forward resque-web instances via Capistrano.

multiple_ssh_tunnels.rb

Capistrano::Configuration.instance(:must_exist).load do
  set :resque_local_start_port, 7070
  set :resque_remote_port, 8282

  def resque_local_ports
    @resque_local_ports ||= Enumerator.new do |yielder|
      current_port = fetch(:resque_local_start_port)
      loop do
        yielder.yield current_port
        current_port += 1
      end
    end
  end
  
  namespace :resque do

    desc "Opens SSH tunnels to all resque-web instances"
    task :web, :roles => :app do
      puts
      puts " ** Opening SSH tunnels to resque-web instances ..."
      pids = []
      app_servers = find_servers(:roles => :app).each
      loop do
        next_server = app_servers.next
        local_port = resque_local_ports.next
        pid = spawn "ssh -L #{local_port}:127.0.0.1:#{resque_remote_port} #{user}@#{next_server} -NT 2>&1 /dev/null"
        Process.detach(pid)
        pids << pid
        puts " ** Open your browser at http://localhost:#{local_port}"
      end

      puts " ** Pids of the SSH tunnels: #{pids.inspect}"
      puts " ** Waiting for INT ..."

      Signal.trap("INT") do
        puts " **  Shutting down ..."
        pids.each do |pid|
          puts " ** Trying to kill #{pid} ..."
          begin
            Process.kill("QUIT", pid)
          rescue
          end
          puts "  * Process #{pid} killed!"
        end
        puts
        puts "  ** All done!"
        puts
        exit
      end

      while true
        sleep 1
      end
    end
  
  end
end