nginx config for having xip.io working with local dev

xipio.conf

upstream xip_app_server {
  server localhost:8080 fail_timeout=0;
}

server {
  listen   80;
  server_name  "~^(?<base_dir>.+)\.([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)\.xip.io$";

  access_log  /var/log/nginx/xip.access.log  main;
  error_log  /var/log/nginx/xip.error.log;

  set $username "jd";

  location / {
    root /home/$username/.sites/$base_dir/;
    index index.html index.htm;
    try_files $uri/index.html $uri @app;
  }

  location @app {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://app_server;
  }
}