anchor.diff:      proxy_set_header        Accept-Encoding "";
     '';
   
  +  upstreamConfig = toString (flip mapAttrsToList cfg.upstreams (name: upstream: ''
  +    upstream ${name} {
  +      ${toString (flip mapAttrsToList upstream.servers (name: server: ''
  +        server ${name} ${optionalString server.backup "backup"};
  +      ''))}
  +    }
  +  ''));
  +
     configFile = pkgs.writeText "nginx.conf" ''
       user ${cfg.user} ${cfg.group};
       error_log stderr;
  
positive.code:         default = {};
        };
  
        virtualHosts = mkOption {
          type = types.attrsOf (types.submodule (import ./vhost-options.nix {
            inherit config lib;
  
negative.code:       ${optionalString (cfg.resolver.addresses != []) ''
          resolver ${toString cfg.resolver.addresses} ${optionalString (cfg.resolver.valid != "") "valid=${cfg.resolver.valid}"};
        ''}
        ${upstreamConfig}
  
        ${optionalString (cfg.recommendedOptimisation) ''
          # optimisation
  