Cannot Add Header in nginx x socket.io Environment

var http=require('http'),
  // Creating a Server Instance
  server = http.createServer(function(req,res){
      res.setHeader("Access-Control-Allow-Origin", "*");
      res.writeHead(200, {'Content-Type':'text/html'});
      res.end('server connected');
  }),
  io=require('socket.io') .listen(server);
  server.listen (9090); // Boot to port 9090
  ・・・

• Currently, Access-Control-Allow-Origin has the host name of the site loading socket.io.js
• Using nginx reverse proxy
• nginx also specified that Access-Control-Allow-Origin should be rewritten, but it should be added instead of rewritten.

• cross-domain error

  XML HttpRequest cannot load http://xxx.xx.xx/socket.io/?EIO=3&transport=polling&t=123456789&sid=USkrjwl.No'Access-Control-Allow-Origin' header is present on the requested resource.Origin' http://hostsite.aa.bb/' is before not allowed access.The response had HTTP status.cusd.403
  

  *Parameter values and URLs are random.There might be a spelling error because I made a handwriting...

XML HttpRequest cannot load http://xxx.xx.xx/socket.io/?EIO=3&transport=polling&t=123456789&sid=USkrjwl.No'Access-Control-Allow-Origin' header is present on the requested resource.http://hostsite.aa.bb/'