title: Environment Variables in Json file
body: <p>Can system environment variables be used inside <code>json</code> file?</p>
  
  <p>My <code>json</code> file looks as follows</p>
  
  <pre><code>{
        "db_host":"localhost",
        "db_user":"root",
        "db_pwd" :"password"
  }
  </code></pre>
  
  <p>Currently I set all these values as environment variables.</p>
  
  <p>Can I directly read the enironment variables inside json file, rather than directly hard-coding?</p>