deploy_special_branch_by_capistrano.rb

1.cap staging deploy -s branch=1626d55d3da9
2.cap staging deploy:rollback #rollback to the previous version
3.添加新的任务-显示服务器当前的代码版本号。在config/deploy.rb文件添加如下代码
  namespace :deploy do
    desc 'Show deployed version'
    task :revision do
      on roles(:app) do
        execute "echo current version is------------------"
        execute "cat #{current_path}/REVISION"
        execute "echo end----------------"
      end
    end
  end
  运行cap staging deploy:version