title: How to add HTTP header in uwsgi logs
body: <p>I have a <code>nginx</code> as proxy, and <code>uWSGI</code> as app server. And I want to add any http headers to uwsgi logs. I can add some <code>var.VAR_NAME</code> to logs.</p>
  
  <p>By docs (<a href="http://uwsgi-docs.readthedocs.io/en/latest/LogFormat.html" rel="nofollow noreferrer">http://uwsgi-docs.readthedocs.io/en/latest/LogFormat.html</a>):</p>
  
  <blockquote>
    <p>%(var.XXX) -> the content of request variable XXX (like var.PATH_INFO, available from
    1.9.21)</p>
  </blockquote>
  
  <p>But this worked only for <code>uwsgi_param</code> from nginx, not for <code>proxy_set_header</code> or smt. like this. </p>