##
  # Sets all the default values. Should only be called once. Use reset
  # if you need to restore values.
 
  def self.set_defaults
    @@default_env ||= {}
    self.reset
 
    mandatory :repository, "repository path"
    mandatory :deploy_to,  "deploy path"
    mandatory :domain,     "server domain"
 
    simple_set(:deploy_timestamped, true,
               :deploy_via,         :export,
               :keep_releases,      5,
               :migrate_args,       "",
               :migrate_target,     :latest,
               :rails_env,          "production",
               :rake_cmd,           "rake",
               :revision,           "head",
               :rsync_cmd,          "rsync",
               :rsync_flags,        ['-azP', '--delete'],
               :ssh_cmd,            "ssh",
               :ssh_flags,          [],
               :sudo_cmd,           "sudo",
               :sudo_flags,         nil,
               :umask,              '02')
 
    set(:current_release)    { File.join(releases_path, releases[-1]) }
    set(:latest_release)     { deploy_timestamped ?release_path: current_release }
    set(:previous_release)   { File.join(releases_path, releases[-2]) }
    set(:release_name)       { Time.now.utc.strftime("%Y%m%d%H%M%S") }
    set(:release_path)       { File.join(releases_path, release_name) }
    set(:releases)           { task.run("ls -x #{releases_path}").split.sort }
 
    set_path :current_path,  "current"
    set_path :releases_path, "releases"
    set_path :scm_path,      "scm"
    set_path :shared_path,   "shared"
 
    set(:sudo_password) do
      state = `stty -g`
 
      raise Vlad::Error, "stty(1) not found" unless $?.success?
 
      begin
        system "stty -echo"
        $stdout.print "sudo password: "
        $stdout.flush
        sudo_password = $stdin.gets
        $stdout.puts
      ensure
        system "stty #{state}"
      end
      sudo_password
    end
  end