anchor.diff:        <%- mirrors.each_with_index do |(name, mirror), index| -%>
           {
               "url": "<%= mirror[:match_url] %>",
  -            "target": "<%= mirror[:target_url] %>"
  +            "path": "<%= mirror[:path] %>"
           }<% if index < mirrors.size - 1 %>,<% end %>
         <%- end -%>
       ]
  
positive.code:     .uniq
      .each do |name|
          mirrors[name] = {
              :match_url  => ENV["MIRROR_#{name}_URL"],
              :target_url => "#{full_host}/mirror/#{name.downcase}/",
          }
      end
  
  
negative.code: <%
  
  mirrors = {}
  ENV.keys.map { |key| key.to_s }
  