you can use nginx as a frontend for your one or many WolfRecorders with just a few lines in the configuration file

 location /wr1/  {
        proxy_pass http://192.168.0.213:80/wr/;
 }

 location /wr2/  {
        proxy_pass http://192.168.0.214:80/wr/;
 }

 .....

or in the following more correct way:

location /wr1/ {
    proxy_pass http://192.168.0.213:80/wr/;
    proxy_redirect /wr/ /wr1/;
    sub_filter '/wr/' '/wr1/';
    sub_filter_once off;
    sub_filter_types text/html text/javascript application/javascript;
    proxy_set_header Accept-Encoding "";
}

location /wr1/wr/ {
    proxy_pass http://192.168.0.213:80/wr/;
    proxy_redirect off;
    sub_filter '/wr/' '/wr1/';
    sub_filter_once off;
    sub_filter_types text/html text/javascript application/javascript;
    proxy_set_header Accept-Encoding "";
}