alternative_manifest.rb

class ApplicationManifest < Moonshine::Manifest
  def ntp
    package 'ntp', :ensure => :latest
    
    case Facter.lsbdistid
    when 'Ubuntu'
      service 'ntp', :alias => 'ntp', :ensure => :running,
        :require => package('ntp'), :pattern => 'ntpd'
    when 'Fedora', 'RedHat'
      service 'ntpd', :alias => 'ntp', :ensure => :running,
        :require => package('ntp'), :pattern => 'ntpd'
    else
      raise "Unsupported distribution: #{_}"
    end
  end
  recipe :ntp
end

application_manifest.rb

class ApplicationManifest < Moonshine::Manifest
  def ntp
    service_name = for_distro('Ubuntu' => 'ntp', 'Fedora' => 'ntpd')

    package 'ntp', :ensure => :latest
    service service_name, :alias => 'ntp', :ensure => :running,
      :require => package('ntp'), :pattern => 'ntpd'
  end
  recipe :ntp

  def for_distro(mapping)
    distribution = Facter.lsbdistid
    if value = mapping[distribution.to_s]
      value
    else
      raise "Unsupported distribution: #{distribution}"
    end
  end
end

imaginary_manifest.rb

class ApplicationManifest < Moonshine::Manifest
  def ntp
    service_name = Facter.case(:lsbdistid, 'Ubuntu' => 'ntp', 'Fedora' => 'ntpd')

    package 'ntp', :ensure => :latest
    service service_name, :alias => 'ntp', :ensure => :running,
      :require => package('ntp'), :pattern => 'ntpd'
  end
  recipe :ntp
end

imaginary_manifest_again.rb

class ApplicationManifest < Moonshine::Manifest
  def ntp
    package 'ntp', :ensure => :latest
    
    service 'ntp',
      :name => Facter.case(:lsbdistid, 'Ubuntu' => 'ntp', 'Fedora' => 'ntpd'),
      :ensure => :running, :require => package('ntp'), :pattern => 'ntpd'
  end
  recipe :ntp
end