title: Check if chef is running as chef-solo
body: <p>I'm using Vagrant and chef-solo to test my cookbooks, but I have one particular recipe that requires chef-server (it uses search). I'd like my default recipe to look like the following:</p>
  
  <pre><code>include_recipe 'some_recipe'
  include_recipe 'some_other_recipe'
  unless running_as_chef_solo?
    include_recipe 'a_recipe_that_requires_chef_server'
  end
  </code></pre>
  
  <p>How can I check whether chef is running as chef-solo from within a cookbook, so I can skip unsupported recipes?</p>