feat(11): initial module with a service

.gitignore

@@ -12,3 +12,4 @@
 */target/
 
 */result
+result

11-single-price-grid-component/default.nix

@@ -1,39 +1,72 @@
-{ pkgs, sbt-derivation }:
+{ pkgs, lib, sbt-derivation }:
 
 let
   package = sbt-derivation.lib.mkSbtDerivation {
-      inherit pkgs;
-      # ...and the rest of the arguments
-      pname = "price-grid-app";
-      version = "0.0.1";
-      src = pkgs.nix-gitignore.gitignoreSource [] ./.;
-      nativeBuildInputs = [ pkgs.nodePackages.tailwindcss ];
-      buildPhase = ''
-        sbt assembly
-        tailwindcss -i ./src/input.css -o ./output.css
-      '';
-      # css path different from ordinary development,
-      # because .gitignore makes it unavailable during nix build
-      # anyway copied to correct place
-      installPhase = ''
-        mkdir -p $out/bin
-        cp target/scala-*/priceGrid-assembly-*.jar $out/bin/
-        mkdir -p $out/bin/dist
-        cp ./output.css $out/bin/dist/output.css
-        cp -r public $out/bin/public
-      '';
+    inherit pkgs;
+    # ...and the rest of the arguments
+    pname = "price-grid-app";
+    version = "0.0.1";
+    src = pkgs.nix-gitignore.gitignoreSource [ ] ./.;
+    nativeBuildInputs = [ pkgs.nodePackages.tailwindcss ];
+    buildPhase = ''
+      sbt assembly
+      tailwindcss -i ./src/input.css -o ./output.css
+    '';
+    # css path different from ordinary development,
+    # because .gitignore makes it unavailable during nix build
+    # anyway copied to correct place
+    installPhase = ''
+      mkdir -p $out/bin
+      cp target/scala-*/priceGrid-assembly-*.jar $out/bin/priceGridApp.jar
+      mkdir -p $out/bin/dist
+      cp ./output.css $out/bin/dist/output.css
+      cp -r public $out/bin/public
+    '';
 
-      depsSha256 = "sha256-aWLqnPXvchtNqpSfXo5sWyK2QFNn1GqToy58cWrML3U=";
-    };
-
-  module = { config, pkgs, ... }: {
-    services.price-grid-app = {
-      enable = true;
-      package = package;
-    };
+    depsSha256 = "sha256-aWLqnPXvchtNqpSfXo5sWyK2QFNn1GqToy58cWrML3U=";
   };
-in
-{
+
+  module = { config, pkgs, ... }:
+    let cfg = config.services.priceGridService;
+    in {
+      options.services.priceGridService = {
+        enable = lib.mkEnableOption "My service";
+
+        port = lib.mkOption {
+          type = lib.types.int;
+          default = 8080;
+          description = "Port to listen on.";
+        };
+
+        host = lib.mkOption {
+          type = lib.types.str;
+          default = "localhost";
+          description = "Host to bind to.";
+        };
+      };
+      config = lib.mkIf cfg.enable {
+        users.groups.price-grid-app-group = { };
+        users.users.price-grid-app-user = {
+          isSystemUser = true;
+          group = "price-grid-app-group";
+        };
+
+        systemd.services.price-grid-app = {
+          description = "My Java Service";
+          wantedBy = [ "multi-user.target" ];
+          after = [ "network.target" ];
+
+          serviceConfig = {
+            ExecStart =
+              "${pkgs.jdk}/bin/java -jar ${package}/bin/priceGridApp.jar -p ${toString cfg.port} --host ${cfg.host}";
+            Restart = "on-failure";
+            User = "price-grid-app-user";
+            Group = "price-grid-app-group";
+          };
+        };
+      };
+    };
+in {
   package = package;
   module = module;
 }

flake.nix

@@ -13,6 +13,7 @@
         pkgs = nixpkgs.legacyPackages.${system};
         price-grid = import ./11-single-price-grid-component/default.nix {
           inherit pkgs sbt-derivation;
+          lib = pkgs.lib;
         };
       in {
         devShells.default = pkgs.mkShell {