gistfile1.rb

task :ask_production_confirmation do
  set(:confirmed) do
    puts <<-WARN

    ========================================================================

      WARNING: You're about to perform actions on production server(s)
      Please confirm that all your intentions are kind and friendly

    ========================================================================

    WARN
    answer = Capistrano::CLI.ui.ask "  Are you sure you want to continue? (Y) "
    if answer == 'Y' then true else false end
  end

  unless fetch(:confirmed)
    puts "\nDeploy cancelled!"
    exit
  end
end

before 'production', :ask_production_confirmation