nginx 泛域名配置，proxy_pass如何使用变量参数

Question

server {
        listen    80;
        server_name *.m.abc.com;
        if ( $host ~* ^([^\.]+)\.([^\.]+)\.([^\.]+)\.([^\.]+)$ ) {
                set $subdomain $1;
                set $mD2 $2.$3.$4;
                set $d2 $2;
                set $d3 $3;
        }
        location / {
                rewrite ^/$                                 /index.jsp?cdm=$subdomain last;
                #proxy_pass  http://m.abc.com/;#这个正确访问网页 
                proxy_pass http://$mD2/; #502 bad Gateway
                #proxy_pass http://$d2.abc.com/; #502 bad Gateway
                #proxy_pass http://${d2}.${d3}.${d4}/; #502 bad Gateway
                #proxy_pass $mD2/; #502 bad Gateway
        }
    }

Answer 1

location ^~ /wap/
{
if ($request_uri ~ /wap/(\d+)/(.+))
{
set $bucketid $1;
set $params $2;
}
proxy_pass http://mx$bucketid.test.com:6601/$params;
}是要在local里面先set?