nixos/atop: Add configuration for atop services, allow to enable netatop, gpuatop, allow setuid wrapper

nixos/modules/programs/atop.nix

@@ -1,6 +1,6 @@
 # Global configuration for atop.
 
-{ config, lib, ... }:
+{ config, lib, pkgs, ... }:
 
 with lib;
 
@@ -12,11 +12,82 @@ in
 
   options = {
 
-    programs.atop = {
+    programs.atop = rec {
 
+      enable = mkEnableOption "Atop";
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.atop;
+        description = ''
+          Which package to use for Atop.
+        '';
+      };
+
+      netatop = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Whether to install and enable the netatop kernel module.
+          '';
+        };
+        package = mkOption {
+          type = types.package;
+          default = config.boot.kernelPackages.netatop;
+          description = ''
+            Which package to use for netatop.
+          '';
+        };
+      };
+
+      atopgpu.enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to install and enable the atopgpud daemon to get information about
+          NVIDIA gpus.
+        '';
+      };
+
+      setuidWrapper.enable = mkOption {
+        type = types.bool;
+        default = cfg.netatop.enable || cfg.atopgpu.enable;
+        description = ''
+          Whether to install a setuid wrapper for Atop. This is required to use some of
+          the features as non-root user (e.g.: ipc information, netatop, atopgpu).
+          Atop tries to drop the root privileges shortly after starting.
+        '';
+      };
+
+      atopsvc.enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to enable the atop service responsible for storing statistics for
+          long-term analysis.
+        '';
+      };
+      atopRotate.enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to enable the atop-rotate timer, which restarts the atop service
+          daily to make sure the data files are rotate.
+        '';
+      };
+      atopacct.enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to enable the atopacct service which manages process accounting.
+          This allows Atop to gather data about processes that disappeared in between
+          two refresh intervals.
+        '';
+      };
       settings = mkOption {
         type = types.attrs;
-        default = {};
+        default = { };
         example = {
           flags = "a1f";
           interval = 5;
@@ -25,12 +96,51 @@ in
           Parameters to be written to <filename>/etc/atoprc</filename>.
         '';
       };
-
     };
   };
 
-  config = mkIf (cfg.settings != {}) {
-    environment.etc.atoprc.text =
-      concatStrings (mapAttrsToList (n: v: "${n} ${toString v}\n") cfg.settings);
-  };
+  config = mkIf cfg.enable (
+    let
+      atop =
+        if cfg.atopgpu.enable then
+          (cfg.package.override { withAtopgpu = true; })
+        else
+          cfg.package;
+      packages = [ atop (lib.mkIf cfg.netatop.enable cfg.netatop.package) ];
+    in
+    {
+      environment.etc = mkIf (cfg.settings != { }) {
+        atoprc.text = concatStrings
+          (mapAttrsToList
+            (n: v: ''
+              ${n} ${toString v}
+            '')
+            cfg.settings);
+      };
+      environment.systemPackages = packages;
+      boot.extraModulePackages = [ (lib.mkIf cfg.netatop.enable cfg.netatop.package) ];
+      systemd =
+        let
+          mkSystemd = type: cond: name: {
+            ${name} = lib.mkIf cond {
+              restartTriggers = packages;
+              wantedBy = [ (if type == "services" then "multi-user.target" else if type == "timers" then "timers.target" else null) ];
+            };
+          };
+          mkService = mkSystemd "services";
+          mkTimer = mkSystemd "timers";
+        in
+        {
+          inherit packages;
+          services =
+            mkService cfg.atopsvc.enable "atop"
+            // mkService cfg.atopacct.enable "atopacct"
+            // mkService cfg.netatop.enable "netatop"
+            // mkService cfg.atopgpu.enable "atopgpu";
+          timers = mkTimer cfg.atopRotate.enable "atop-rotate";
+        };
+      security.wrappers =
+        lib.mkIf cfg.setuidWrapper.enable { atop = { source = "${atop}/bin/atop"; }; };
+    }
+  );
 }