title: NodeJS + ExpressJS, unable to read environment variable
body: <p>I am setting a variable in Express.js as follows: <code>app.set('HOST', 'demo.sample.com');</code>. However, if I try to read this variable, I get <code>undefined</code> as the output. I am reading the variable using <code>process.env.HOST</code>. Nevertheless, if I try to read it using <code>app.get('HOST')</code>, I get the correct value.</p>
  
  <p>I cannot use <code>app.get('HOST')</code> since I am reading the variable in another file too — a file that does not contain a reference to the Express.js app variable.</p>
  
  <p>How do I get the value using <code>process.env.HOST</code>?</p>