auth_request_set into variable and lua

[djczaski]

Trying to get a header from an auth_request into a variable and use it from
Lua with no luck.  This was the simple example I tried.  

      location = /auth {
           add_header    X-Boo    "Hello World";
           return 204;
        }

        location /test {
            auth_request /auth;
            auth_request_set $test $upstream_http_x_boo;
            add_header X-BooHoo $test;

            content_by_lua '
                ngx.say("(" .. ngx.var.test .. ")")
            ';
        }

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,233582,233582#msg-233582