add nixos module and overlay

flake.nix

@@ -10,12 +10,16 @@
       forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
       nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
     in {
+      overlay = final: prev: {
+        pots = self.packages.${prev.system}.pots;
+      };
+      nixosModule = import ./module.nix;
       packages = forAllSystems (system:
         let pkgs = nixpkgsFor.${system};
         in {
           pots = pkgs.buildGoModule {
             pname = "pots";
-            version = "v0.0.1";
+            version = "v0.0.2";
             src = ./.;
             vendorHash = "sha256-pQpattmS9VmO3ZIQUFn66az8GSmB4IvYhTTCFn6SUmo=";
           };

main.go

@@ -132,7 +132,8 @@ func (apiHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 }
 
 func main() {
-	listen := flag.String("listen", ":8888", "listen string")
+	port := flag.Int("port", 8888, "port to listen on")
+	ip := flag.String("ip", "127.0.0.1", "ip to listen on")
 	flag.Parse()
 
 	mux := http.NewServeMux()
@@ -147,7 +148,7 @@ func main() {
 	})
 
 	s := &http.Server{
-		Addr:    *listen,
+		Addr:    fmt.Sprintf("%s:%d", *ip, *port),
 		Handler: mux,
 	}
 

module.nix

@@ -0,0 +1,91 @@
+{ lib, config, pkgs, inputs, ... }:
+let cfg = config.services.pots;
+in {
+  options = with lib; {
+    services.pots = {
+      enable = lib.mkEnableOption "Enable pots";
+
+      port = mkOption {
+        type = types.int;
+        default = 8888;
+        description = ''
+          Port to listen on string.
+        '';
+      };
+
+      user = mkOption {
+        type = with types; oneOf [ str int ];
+        default = "pots";
+        description = ''
+          The user the service will use.
+        '';
+      };
+
+      group = mkOption {
+        type = with types; oneOf [ str int ];
+        default = "pots";
+        description = ''
+          The group the service will use.
+        '';
+      };
+
+      keyPath = mkOption {
+        type = types.path;
+        default = "";
+        description = ''
+          Path to the GitHub API key file
+        '';
+      };
+
+      dataDir = mkOption {
+        type = types.path;
+        default = "/var/lib/pots";
+        description = "Path pots home directory";
+      };
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.pots;
+        defaultText = literalExpression "pkgs.pots";
+        description = "The package to use for pots";
+      };
+
+      envFile = mkOption {
+        type = types.path;
+        default = "/run/secrets/pots_env_file";
+        description = ''
+          Path to a file containing the pots token information
+        '';
+      };
+    };
+  };
+
+  config = lib.mkIf (cfg.enable) {
+    users.groups.${cfg.group} = { };
+    users.users.${cfg.user} = {
+      description = "pots service user";
+      isSystemUser = true;
+      home = "${cfg.dataDir}";
+      createHome = true;
+      group = "${cfg.group}";
+    };
+
+    systemd.services.pots = {
+      enable = true;
+      description = "pots server";
+      wantedBy = [ "network-online.target" ];
+      after = [ "network-online.target" ];
+
+      environment = { HOME = "${cfg.dataDir}"; };
+
+      serviceConfig = {
+        User = cfg.user;
+        Group = cfg.group;
+
+        ExecStart =
+          "${cfg.package}/bin/pots -port ${cfg.port}";
+        EnvironmentFile = cfg.envFile;
+      };
+    };
+  };
+}