Use Puppet to ensure Ubuntu can get the latest Puppet

puppetlabs.pp

class puppetlabs {
  # Install Puppet repository and call apt-get update
  case $operatingsystem {
    ubuntu: {
      $key = "4BD6EC30"
      exec { 'apt-key puppetlabs':
        path    => "/bin:/usr/bin",
        unless  => "apt-key list | grep '${key}' | grep -v expired",
        command => "apt-key adv --keyserver keyserver.ubuntu.com --recv-keys ${key}",      
      }
      
      file { 'apt source puppetlabs':
        ensure  => present,
        path    => "/etc/apt/sources.list.d/puppetlabs.list",
        content => "deb http://apt.puppetlabs.com ${lsbdistcodename} main\n",
      }
      
      file { 'old puppet list':
        path   => "/etc/apt/sources.list.d/puppet.list",
        ensure => absent,
      }

      exec { 'apt-get update puppetlabs':
        command => "/usr/bin/apt-get update",
        require => [Exec['apt-key puppetlabs'], File['apt source puppetlabs']],
        creates => "/var/lib/apt/lists/apt.puppetlabs.com_dists_${lsbdistcodename}_main_binary-${architecture}_Packages",
        timeout => 3600,
      }
    }
  }
}

To quickly use:

curl -O https://raw.github.com/gist/3726289/b6a10fd055eb9ea20f1c30d27e6d3f69fb1fa493/puppetlabs.pp ; sudo puppet apply -e 'include puppetlabs'