title: no method error for nginx chef recipe
body: <p>I'm trying to use the recipe for Nginx from the Chef opscode website, <a href="http://community.opscode.com/cookbooks/nginx" rel="nofollow">http://community.opscode.com/cookbooks/nginx</a></p>
  
  <p>When I run the recipe, it's triggering a no method error that traces back to this line  of code from source.rb. This is line 28 referred to in the trace. </p>
  
  <pre><code>nginx_url = node['nginx']['source']['url'] ||
    "http://nginx.org/download/nginx-#{node['nginx']['source']['version']}.tar.gz"
  </code></pre>
  
  <p>Can anyone explain what the problem might be? I'm following along with this Railscast <a href="http://railscasts.com/episodes/339-chef-solo-basics?view=asciicast" rel="nofollow">http://railscasts.com/episodes/339-chef-solo-basics?view=asciicast</a> where the recipe (an older version obviously) is working for Ryan. </p>
  
  <pre><code>NoMethodError: undefined method `[]' for nil:NilClass
  /var/chef/cookbooks/nginx/recipes/source.rb:28:in `from_file'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/mixin/from_file.rb:30:in `instance_eval'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/mixin/from_file.rb:30:in `from_file'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/cookbook_version.rb:346:in `load_recipe'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context.rb:151:in `load_recipe'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context.rb:132:in `block in include_recipe'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context.rb:131:in `each'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context.rb:131:in `include_recipe'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/dsl/include_recipe.rb:26:in `include_recipe'
  /var/chef/cookbooks/main/recipes/default.rb:4:in `from_file'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/mixin/from_file.rb:30:in `instance_eval'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/mixin/from_file.rb:30:in `from_file'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/cookbook_version.rb:346:in `load_recipe'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context.rb:151:in `load_recipe'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context/cookbook_compiler.rb:139:in `block in compile_recipes'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context/cookbook_compiler.rb:137:in `each'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context/cookbook_compiler.rb:137:in `compile_recipes'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context/cookbook_compiler.rb:74:in `compile'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/run_context.rb:86:in `load'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/client.rb:224:in `setup_run_context'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/client.rb:467:in `do_run'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/client.rb:200:in `run'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/application.rb:190:in `run_chef_client'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/application/solo.rb:239:in `block in run_application'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/application/solo.rb:231:in `loop'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/application/solo.rb:231:in `run_application'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.4/lib/chef/application.rb:73:in `run'
  </code></pre>