title: How to prevent variable substitution in puppet-nginx module
body: <p>Not 100% sure if this is a puppet question or module specific (<a href="https://github.com/jfryman/puppet-nginx" rel="nofollow">jfryman/puppet-nginx</a>) but using this puppet code below, my goal is to preserve the variable $upstream that is written to the config file. However it is always substituted for the actual value. The reason for the substitution is detailed <a href="http://tenzer.dk/nginx-with-dynamic-upstreams/" rel="nofollow">here</a></p>
  
  <pre><code>$upstream = "http://acme.unix.local"
  nginx::resource::vhost { 'acme.co':
    listen_port =&gt; 8080,
    server_name =&gt; [
      'www.acme.co'
    ],
    proxy =&gt; "$upstream", 
  }
  </code></pre>
  
  <p>This is intended ,</p>
  
  <pre><code>location / {
    proxy_pass $upstream; 
  }
  </code></pre>
  
  <p>Unfortunately I am getting this result ,</p>
  
  <pre><code>location / {
    proxy_pass http://acme.unix.local;
  }
  </code></pre>