Create networking abstraction

modules/system/services/dns.nix

@@ -0,0 +1,73 @@
+{
+  config,
+  self,
+  lib,
+  lib',
+  ...
+}:
+let
+  cfg = config.custom.services.dns;
+  netCfg = config.custom.networking;
+in
+{
+  options.custom.services.dns.enable = lib.mkEnableOption "";
+
+  config = lib.mkIf cfg.enable {
+    # meta.ports = {
+    #   tcp = [ 53 ];
+    #   udp = [ 53 ];
+    # };
+
+    services = {
+      unbound = {
+        enable = true;
+
+        settings = {
+          server = {
+            interface = [ netCfg.overlay.interface ];
+            access-control = [
+              "${netCfg.overlay.networkAddress}/${toString netCfg.overlay.prefixLength} allow"
+            ];
+
+            local-zone = "\"${netCfg.overlay.domain}.\" static";
+            local-data =
+              let
+                nodeRecords =
+                  netCfg.nodes
+                  |> lib.map (node: "\"${node.hostname}.${node.overlay.domain}. A ${node.overlay.address}\"");
+                serviceRecords =
+                  self.nixosConfigurations
+                  |> lib.attrValues
+                  |> lib.concatMap (
+                    host:
+                    host.config.meta.domains.local
+                    |> lib.filter (domain: lib'.isPrivateDomain domain)
+                    |> lib.map (domain: "\"${domain}. A ${host.config.custom.networking.overlay.address}\"")
+                  );
+              in
+              nodeRecords ++ serviceRecords;
+          };
+
+          forward-zone = lib.singleton {
+            name = ".";
+            forward-addr = [
+              "1.1.1.1"
+              "8.8.8.8"
+            ];
+          };
+        };
+      };
+
+      nebula.networks.mesh.firewall.inbound = lib.singleton {
+        port = 53;
+        proto = "any";
+        host = "any";
+      };
+    };
+
+    systemd.services.unbound = {
+      requires = [ netCfg.overlay.systemdUnit ];
+      after = [ netCfg.overlay.systemdUnit ];
+    };
+  };
+}