create version-aware executables to provide multiple npm installations

.travis.yml

@@ -25,3 +25,5 @@ before_install:
 script: "rake test"
 
 gemfile: .gemfile
+
+sudo: false

lib/puppet/parser/functions/npm_version.rb

@@ -0,0 +1,11 @@
+module Puppet::Parser::Functions
+  newfunction(:npm_version, :type => :rvalue) do |args|
+    node_unpack_folder = args.shift
+    version            = `#{node_unpack_folder}/bin/npm -v`
+
+    # the version will be extracted from the CLI.
+    # the output contains a line break, but this line break causes weird
+    # symlink names, so the version needs to be stripped.
+    version.strip
+  end
+end

manifests/install.pp

@@ -100,6 +100,10 @@
   $node_symlink_target = "${node_unpack_folder}/bin/node"
   $node_symlink = "${node_target_dir}/node-${node_version}"
 
+  $npm_version    = npm_version($node_unpack_folder)
+  $npm_target_dir = "${node_unpack_folder}/bin"
+  $npm_filename   = "${node_target_dir}/npm-${npm_version}"
+
   ensure_resource('file', 'nodejs-install-dir', {
     ensure => 'directory',
     path   => $::nodejs::params::install_dir,
@@ -207,4 +211,13 @@
       ],
     }
   }
+  else {
+    $npm_template_name = "${module_name}/npm.erb"
+
+    file { $npm_filename:
+      ensure  => file,
+      mode    => '0777',
+      content => template($npm_template_name)
+    }
+  }
 }

templates/npm.erb

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+<%= @node_symlink %> <%= @node_unpack_folder %>/bin/npm $@