server{ .. .. return http://www.baidu.com; }
server{ .. .. return 200 "error"; }
server{ .. .. return 200 "$host$request_uri"; }
server{ .. .. return 200 "<html><script>window.location.href='$host$request_uri'</script></html>"; }
server{ .. .. return 200 '{"name":"muyu","id":1}'; }