Load nbd module

gistfile1.txt

  exec { "insert_module_nbd":
    command => "/bin/echo 'nbd' > /etc/modules",
    unless  => "/bin/grep 'nbd' /etc/modules",
  }
  exec { "/sbin/modprobe nbd":
    unless => "/bin/grep -q '^nbd ' '/proc/modules'"
  }