output.txt

PS C:\ruby> chef-apply package.rb
Recipe: (chef-apply cookbook)::(chef-apply recipe)
  * log[lolwut ruby] action write (skipped due to only_if)
PS C:\ruby> vim .\package.rb
PS C:\ruby> chef-apply package.rb
Recipe: (chef-apply cookbook)::(chef-apply recipe)
  * log[lolwut ruby] action write
PS C:\ruby> chef-apply package.rb -l info
[2014-06-26T13:16:07-04:00] INFO: Run List is []
[2014-06-26T13:16:07-04:00] INFO: Run List expands to []
Recipe: (chef-apply cookbook)::(chef-apply recipe)
  * log[lolwut ruby] action write[2014-06-26T13:16:07-04:00] INFO: Processing log[lolwut ruby] action write ((chef-apply cookbook)::(chef-apply recipe) line 9)
[2014-06-26T13:16:07-04:00] INFO: Chef 11.12.8-2 is already installed

windows_package.rb

# Only do something if a package is/is not installed on windows, by product code

class MsiHelper
  include Chef::ReservedNames::Win32::API::Installer

  def installed?(product_code)
    get_installed_version(product_code)
  end
end

log "lolwut ruby" do
  message "Chef 11.12.8-2 is already installed"
  only_if { MsiHelper.new.installed?('{0CA254AC-3ACB-4830-9C2F-407F6232BB9C}') }
end