don't mount matlab.iso if matlab is installed

manifests/install.pp

@@ -57,12 +57,12 @@ class matlab::install(      # $namevar matlab release version
   # TODO: since there seem to be different iso's for each version, maybe
   # we should add a unique identifier based on the $iso variable here.
   file { "${vardir}/MATHWORKS-${name_}.iso":
-    ensure  => present,
-    owner   => root,
-    group   => root,
-    mode    => '0600',    # u=rw,go=
+    ensure  => link,
+    #owner   => root,
+    #group   => root,
+    #mode    => '0600',    # u=rw,go=
     backup  => false,  # don't backup to filebucket!
-    source  => $iso,
+    target  => $iso,
     alias   => "matlab_iso.${name_}",
     require => File["/mnt/matlab-${name_}"],
   }
@@ -71,16 +71,22 @@ class matlab::install(      # $namevar matlab release version
   # TODO: replace this mount with an exec that has an:
   # onlyif => the_binary_is_not_installed so that a normal machine
   # doesn't need to have the iso mounted all the time...
-  mount { "/mnt/matlab-${name_}":
-    ensure  => mounted,
-    atboot  => true,
-    device  => "${vardir}/MATHWORKS-${name_}.iso",
-    fstype  => 'iso9660',
-    options => 'loop,ro',
-    dump    => '0',    # fs_freq: 0 to skip file system dumps
-    pass    => '0',    # fs_passno: 0 to skip fsck on boot
+  #mount { "/mnt/matlab-${name_}":
+  #  ensure  => mounted,
+  #  atboot  => true,
+  #  device  => "${vardir}/MATHWORKS-${name_}.iso",
+  #  fstype  => 'iso9660',
+  #  options => 'loop,ro',
+  #  dump    => '0',    # fs_freq: 0 to skip file system dumps
+  #  pass    => '0',    # fs_passno: 0 to skip fsck on boot
+  #  alias   => "matlab_mount.${name_}",
+  #  require => [File["matlab_iso.${name_}"]],
+  #}
+
+  exec {"mount -t iso9660 -o loop,ro ${vardir}/MATHWORKS-${name_}.iso /mnt/matlab-${name_}" :
     alias   => "matlab_mount.${name_}",
-    require => [File["matlab_iso.${name_}"]],
+    unless  => "test -e ${install_destination}/bin/matlab",
+    require => [File["matlab_iso.${name_}"]]
   }
 
   # build installer parameters file in our scratch directory