gistfile1.rb

ENV['hosts'] = ['host1', 'host2', {:web => 'host3'}, {:app => 'host4'}]

def deploy
  # will run on every host defined in ENV['hosts'], despite if it is in role
  method_which_will_run_on_every_defined_host
  run_once { run_tests }
  web_role
  app_role 
end

def web_role
  # will run only on :web hosts
  return unless role? :web
  copy_static
  clear_cache
end

def app_role
  # will run only on :app hosts
  return unless role? :app
  copy_code
  run_migrate
end

def run_tests; end
def copy_static; end
def clear_cache; end
def copy_code; end
def run_migrate; end
def method_which_will_run_on_every_defined_host; end

$ topor deploy