Gitorious Debian/Ubuntu multiple package install, multiple OSes

gistfile1.pp

class gitorious::example
  case $operatingsystem {
    CentOS: {
      case $operatingsystemrelease {
        /^5/: {
          $package_list = ["monit", "memcached", "ImageMagick","gcc-c++","zlib-devel","make","wget","libxml2","libxml2-devel","libxslt","libxslt-devel","gcc","ruby-devel","openssl","curl-devel"]
        }
        default: {
          $package_list = ["monit", "memcached", "ImageMagick","gcc-c++","zlib-devel","make","wget","libxml2","libxml2-devel","libxslt","libxslt-devel","gcc","ruby-devel","openssl","libcurl-devel"]
        }
      }
      $monit_conf_dir = "/etc/monit.d"
      $monit_conf_file = "/etc/monit.conf"
    }
    Ubuntu: {
      $package_list = ["monit", "memcached", "imagemagick","gobjc++","libghc-zlib-dev","make","wget","libxml2","libxml2-dev","libxslt1.1","libxslt1-dev","gcc","ruby-dev","openssl","libcurl4-openssl-dev","sendmail","ruby-stomp", "ruby-daemons", "libreadline6-dev", "libicu48", "libicu-dev", "libonig2", "libtinfo-dev"]
      $monit_conf_dir = "/etc/monit/conf.d"
      $monit_conf_file="/etc/monit/monitrc"
    }
  }

  package { $package_list: ensure => installed }
  file {"${monit_conf_file}":
    ensure => present,
    owner => "root",
    group => "root",
    mode => "0600",
    content => template("gitorious/etc/example.conf.erb"),
    require => Package["example"],
  }
 service { "example":
    name => "${example_service_name}",
    ensure => running,
    enable => true,
    require => Package[$package_list]
  }