attic-client: init module

modules/misc/news/2026/07/2026-07-06_00-46-00.nix

@@ -0,0 +1,9 @@
+{
+  time = "2026-07-06T00:46:00+00:00";
+  condition = true;
+  message = ''
+    A new module is available: `programs.attic-client`.
+
+    It manages the client configuration for the Attic Nix binary cache.
+  '';
+}

modules/programs/attic-client.nix

@@ -0,0 +1,97 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  inherit (lib)
+    mkOption
+    types
+    ;
+
+  cfg = config.programs.attic-client;
+
+  settingsFormat = pkgs.formats.toml { };
+in
+{
+  options.programs.attic-client = {
+    enable = lib.mkEnableOption "the attic binary cache client";
+
+    package = lib.mkPackageOption pkgs "attic-client" {
+      nullable = true;
+    };
+
+    settings = mkOption {
+      inherit (settingsFormat) type;
+      default = { };
+      example = lib.literalExpression ''
+        {
+          default-server = "myserver";
+          servers.myserver = {
+            endpoint = "https://myserver.org";
+            token-file = "/run/secrets/attic-token";
+          };
+        }
+      '';
+      description = ''
+        Configuration written to
+        {file}`$XDG_CONFIG_HOME/attic/config.toml`.
+
+        See <https://github.com/zhaofengli/attic> for the available options.
+      '';
+    };
+
+    watchStore = mkOption {
+      type = types.listOf types.str;
+      default = [ ];
+      example = [ "mycacheserver:mycache" ];
+      description = ''
+        Caches to push new store paths to via `attic watch-store`.
+        Format: `server:cache` (or just `cache` to use the default server).
+
+        This relies on systemd and is only supported on Linux.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = cfg.watchStore == [ ] || pkgs.stdenv.hostPlatform.isLinux;
+        message = "programs.attic-client.watchStore requires systemd and is only supported on Linux.";
+      }
+      {
+        assertion = cfg.watchStore == [ ] || cfg.package != null;
+        message = "programs.attic-client.watchStore requires programs.attic-client.package to be set.";
+      }
+    ];
+
+    home.packages = lib.mkIf (cfg.package != null) [ cfg.package ];
+
+    xdg.configFile."attic/config.toml" = lib.mkIf (cfg.settings != { }) {
+      source = settingsFormat.generate "attic-config.toml" cfg.settings;
+    };
+
+    systemd.user.services = lib.mkIf (cfg.watchStore != [ ]) (
+      lib.listToAttrs (
+        map (
+          cache:
+          lib.nameValuePair "attic-watch-store--${lib.replaceStrings [ ":" ] [ "-" ] cache}" {
+            Unit.Description = "Push new store paths to the attic cache ${cache}";
+
+            Install.WantedBy = [ "default.target" ];
+
+            Service = {
+              ExecStart = "${lib.getExe cfg.package} watch-store ${cache}";
+              Restart = "always";
+              RestartSec = 30;
+            };
+          }
+        ) cfg.watchStore
+      )
+    );
+  };
+
+  meta.maintainers = [ lib.maintainers.swarsel ];
+}