cap avoid too fast restart of mongrel-cluster

deploy.rb

namespace :deploy do
  task :start, :roles => :app do
    sudo "mongrel_rails cluster::start -C #{mongrel_conf}"
  end

  task :stop, :roles => :app do
    sudo "mongrel_rails cluster::stop -C #{mongrel_conf}"

    y = {
      "port" => 3000, "servers" => 2, "pid_file" => "tmp/pids/mongrel.pid"
    }.merge(YAML.load(capture("cat #{mongrel_conf}")))
    dir, file, port, servers = %w(cwd pid_file port servers).map{|k| y[k]}

    ports = port...(port + servers)
    dir = File.join(dir, File.dirname(file))
    ext = File.extname(file)
    name = File.basename(file, ext)
    files = ports.map{|p| File.join(dir, [name, p].join('.') + ext)}
    cmd = "test #{files.map{|v| '-f ' + v}.join(' -o ')} || echo t"
    
    sleep 1 until capture(cmd).strip == 't'
  end

  task :restart, :roles => :app do
    find_and_execute_task "deploy:stop"
    find_and_execute_task "deploy:start"
  end
end