puppet npm provider

npm.rb

# NPM provider for Puppet.
#
# Author::    Simo Kinnunen
# Copyright:: Copyright (c) 2012 CyberAgent, Inc.
# See::       http://rcrowley.org/talks/sv-puppet-2011-01-11/
# See::       https://github.com/newLoki/puppet-npm/
# See::       https://github.com/rcrowley/puppet-pip/

require 'puppet/provider/package'

Puppet::Type.type(:package).provide :npm, :parent => ::Puppet::Provider::Package do

  desc "Node.js packages via `npm`."

  has_feature :installable, :uninstallable, :upgradeable, :versionable

  def self.parse(line)
    if line.rstrip =~ / ([^ ]+)@([^ ]+)$/
      {:ensure => $2, :name => $1, :provider => name}
    else
      nil
    end
  end

  def self.instances
    packages = []
    cmd = which("npm") or return []
    execpipe "#{cmd} -g ls" do |process|
      process.collect do |line|
        next unless options = parse(line)
        packages << new(options)
      end
    end
    packages
  end

  def install
    args = %w{install -g}
    case @resource[:ensure]
    when String
      args << "#{@resource[:name]}@#{@resource[:ensure]}"
    when :latest
      args << "#{@resource[:name]}@latest"
    else
      args << @resource[:name]
    end
    lazy_npm *args
  end

  def uninstall
    lazy_npm "uninstall", "-g", @resource[:name]
  end

  def latest
    cmd = which("npm") or return nil
    output = execute ["#{cmd}", "view", "#{resource[:name]}", "version"]
    self.fail "Could not get latest for #{resource[:name]}, npm not happy" if output.include?("npm not ok")
    output.strip
  end

  def update
    install
  end

  def query
    self.class.instances.each do |package|
      return package.properties if @resource[:name] == package.name
    end
    return nil
  end

  private
  def lazy_npm(*args)
    npm *args
  rescue NoMethodError => e
    if pathname = which('npm')
      self.class.commands :npm => pathname
      npm *args
    else
      raise e
    end
  end

end