nginx-site.conf

rewrite ^/sitemap1.xml.gz /sitemaps/$host/sitemap1.xml.gz last;
rewrite ^/sitemap_index.xml.gz /sitemaps/$host/sitemap_index.xml.gz last;

sitemap.rb

require 'rubygems'
require 'sitemap_generator'


Constants::HOSTS.each do |host, locale|
  SitemapGenerator::Sitemap.default_host = "http://#{host}"


  SitemapGenerator::Sitemap.public_path = "public/sitemaps/#{host}"
  SitemapGenerator::Sitemap.sitemaps_path = ''


  SitemapGenerator::Sitemap.create do
    add root_path, priority: 1

    Property.find_each do |property|
      add property_path(property),
          priority: 0.8,
          lastmod: (property.updated_at || property.created_at),
          alternates: Constants::HOSTS.map { |h, l|
            if locale != l
              {
                href: property_url(property, host: h),
                lang: l
              }
            end
          }.compact
    end


  end

  SitemapGenerator::Sitemap.ping_search_engines
end