snippet.rb

before "deploy:symlink", "deploy:check_app_dependencies"

namespace :deploy do
  desc "Checks for required dependencies by starting the application"
  task :check_app_dependencies, :roles => :app do
    app_env = fetch(:rails_env, "production")
    run "cd #{release_path};  RAILS_ENV=#{app_env} ./script/runner ''"
    # TODO: anything required for rollback?
  end
end