WIP: DNS: split the zone generation out of trust-dns

this is in preparation for upstreaming parts of this into nixpkgs

hosts/by-name/servo/services/trust-dns.nix

@@ -60,7 +60,7 @@
       zone-dir = "/var/lib/trust-dns";
       zone-wan = "${zone-dir}/wan/uninsane.org.zone";
       zone-lan = "${zone-dir}/lan/uninsane.org.zone";
-      zone-template = pkgs.writeText "uninsane.org.zone.in" config.sane.services.trust-dns.generatedZones."uninsane.org";
+      zone-template = config.sane.services.trust-dns.zones."uninsane.org".file;
     in pkgs.writeShellScriptBin "named" ''
       # compute wan/lan values
       mkdir -p ${zone-dir}/{ovpn,wan,lan}

modules/default.nix

@@ -2,6 +2,7 @@
 
 {
   imports = [
+    ./dns.nix
     ./feeds.nix
     ./fs
     ./ids.nix

modules/services/trust-dns.nix

@@ -7,50 +7,6 @@ with lib;
 let
   cfg = config.sane.services.trust-dns;
   toml = pkgs.formats.toml { };
-  recordFormatters = {
-    # quote rules for zone files:
-    # - any character may be encoded by `\DDD`, where `DDD` represents its ascii value in base 8.
-    # - any non-digit `X` may be encoded by `\X`.
-    # - stated in: <https://www.ietf.org/rfc/rfc1035.txt>: 5.1 Format
-    # - visible in <trust-dns:crates/proto/src/serialize/txt/zone_lex.rs:escape_seq>
-    # for us, we can just replace `\` => `\\ and `"` -> `\"`
-    TXT = value: "\"" + (lib.escape [ "\\" "\"" ] value) + "\"";
-  };
-  fmtRecord = proto: rrtype: name: value:
-    let
-      formatter = recordFormatters."${rrtype}" or lib.id;
-    in
-      "${name}\t${proto}\t${rrtype}\t${formatter value}";
-  fmtRecordList = proto: rrtype: name: values: concatStringsSep
-    "\n"
-    (map (fmtRecord proto rrtype name) values)
-  ;
-  fmtRecordAttrs = proto: rrtype: rrAttrs:
-    concatStringsSep
-      "\n"
-      (
-        attrValues (
-          mapAttrs
-            (name: fmtRecordList proto rrtype name)
-            rrAttrs
-        )
-      );
-  fmtIncludes = paths: concatStringsSep
-    "\n"
-    (map (path: "$INCLUDE ${path}") paths);
-
-  genZone = zcfg: ''
-    $TTL ${toString zcfg.TTL}
-    ${fmtRecordAttrs "IN" "SOA" zcfg.inet.SOA}
-    ${fmtRecordAttrs "IN" "A" zcfg.inet.A}
-    ${fmtRecordAttrs "IN" "CNAME" zcfg.inet.CNAME}
-    ${fmtRecordAttrs "IN" "MX" zcfg.inet.MX}
-    ${fmtRecordAttrs "IN" "NS" zcfg.inet.NS}
-    ${fmtRecordAttrs "IN" "SRV" zcfg.inet.SRV}
-    ${fmtRecordAttrs "IN" "TXT" zcfg.inet.TXT}
-    ${fmtIncludes zcfg.include}
-    ${zcfg.extraConfig}
-  '';
 
   configFile = toml.generate "trust-dns.toml" {
     listen_addrs_ipv4 = cfg.listenAddrsIPv4;
@@ -58,20 +14,10 @@ let
       mapAttrs (zname: zcfg: rec {
         zone = if zcfg.name == null then zname else zcfg.name;
         zone_type = "Primary";
-        file = if zcfg.file == null then
+        file = zcfg.file;
-          pkgs.writeText "${zone}.zone" (genZone zcfg)
-        else
-          zcfg.file;
       }) cfg.zones
     );
   };
-
-  # (listOf ty) type which also accepts single-assignment of `ty`.
-  # it's used to allow the user to write:
-  #   CNAME."foo" = "bar";
-  # as shorthand for
-  #   CNAME."foo" = [ "bar" ];
-  listOrUnit = ty: types.coercedTo ty (elem: [ elem ]) (types.listOf ty);
 in
 {
   options = {
@@ -106,89 +52,37 @@ in
       };
       # reference <nixpkgs:nixos/modules/services/web-servers/nginx/vhost-options.nix>
       zones = mkOption {
-        type = types.attrsOf (types.submodule {
+        type = types.attrsOf (types.submodule ({ config, name, ... }: {
           options = {
             name = mkOption {
               type = types.nullOr types.str;
               description = "zone name. defaults to the attribute name in zones";
+              default = name;
+            };
+            text = mkOption {
+              type = types.nullOr types.str;  # TODO: types.lines?
               default = null;
             };
-            TTL = mkOption {
-              type = types.int;
-              description = "default TTL";
-              default = 3600;
-            };
-            include = mkOption {
-              type = types.listOf types.str;
-              description = "paths of other zone files to $INCLUDE into this one";
-              default = [];
-            };
-            extraConfig = mkOption {
-              type = types.lines;
-              description = "extra lines to append to the zone file";
-              default = "";
-            };
-            inet = {
-              SOA = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "Start of Authority record(s)";
-                default = {};
-              };
-              A = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "IPv4 address record(s)";
-                default = {};
-              };
-              CNAME = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "canonical name record(s)";
-                default = {};
-              };
-              MX = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "mail exchanger record(s)";
-                default = {};
-              };
-              NS = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "name server record(s)";
-                default = {};
-              };
-              SRV = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "service record(s)";
-                default = {};
-              };
-              TXT = mkOption {
-                type = types.attrsOf (listOrUnit types.str);
-                description = "text record(s)";
-                default = {};
-              };
-            };
-
             file = mkOption {
-              type = types.nullOr types.str;
+              type = types.nullOr types.str;  # TODO: types.path?
-              default = null;
               description = ''
-                instead of using the generated zone file, use the specified path (user should populate the file specified here).
+                runtime path to a .zone file.
+                if omitted, will be generated from the `text` option.
               '';
             };
           };
-        });
+
+          config = {
+            file = lib.mkIf (config.text != null) (pkgs.writeText "${config.name}.zone" config.text);
+          };
+        }));
         default = {};
         description = "Declarative zone config";
       };
-
-      generatedZones = mkOption {
-        type = types.attrsOf types.str;
-        description = "generated zone text for each zone";
-      };
     };
   };
 
   config = mkIf cfg.enable {
-    sane.services.trust-dns.generatedZones = mapAttrs (zone: zcfg: genZone zcfg) cfg.zones;
-
     sane.ports.ports."53" = {
       protocol = [ "udp" "tcp" ];
       visibleTo.lan = true;