iiab/roles/calibre-web/templates/calibre-web-nginx.conf.j2

location /books/ {
    proxy_set_header        Host            $http_host;
    proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header        X-Scheme        $scheme;
    proxy_set_header        X-Script-Name   /books;
    proxy_pass http://127.0.0.1:8083;
}