l: add hass module

lass/3modules/default.nix

@@ -4,6 +4,7 @@ _:
     ./dnsmasq.nix
     ./ejabberd
     ./folderPerms.nix
+    ./hass.nix
     ./hosts.nix
     ./mysql-backup.nix
     ./news.nix

lass/3modules/hass.nix

@@ -0,0 +1,34 @@
+{ config, lib, pkgs, ... }:
+with import <stockholm/lib>;
+let
+
+  cfg = config.lass.hass;
+
+in {
+  options.lass.hass = {
+    config = mkOption {
+      default = {};
+      type =  with lib.types; let
+          valueType = nullOr (oneOf [
+            bool
+            int
+            float
+            str
+            (attrsOf valueType)
+            (listOf valueType)
+          ]) // {
+            description = "Yaml value";
+            emptyValue.value = {};
+          };
+        in valueType;
+    };
+  };
+
+  config =
+    assert versionOlder version "20.09";
+    mkIf (cfg.config != {})
+     {
+      services.home-assistant.config = cfg.config;
+    };
+}
+