app.js

// My login page is getting a redirect loop. This wasn't happening on AWS though.
app.get('/login', forceHttps, users.login);

// I know for sure this function 'forceHttps' is the issue, because I changed this...
app.get('/privacy', routes.privacy);
// ... to this ...
app.get('/privacy', forceHttps, routes.privacy);
// ... and the privacy page is also having the redirect loop now.

// code

function forceHttps(req, res, next){
  if ('development' !== app.get('env') && !req.connection.encrypted) {
    return res.redirect('https://' + req.headers.host + req.url);
  }
  return next();
}