nixos: define user limits

nixos/users.nix

@@ -1,7 +1,5 @@
-{ pkgs, ... }:
-{
-  users.users =
-    let
+{ lib, ... }:
+let
   adminGroups = [
     "adm"
     "named"
@@ -10,18 +8,49 @@
     "tuxcord"
     "wheel"
   ];
-    in
-    {
-      error = {
+
+  mkUser = name: uid: options: {
+    users.users.${name} = {
       isNormalUser = true;
-        shell = pkgs.fish;
-        extraGroups = adminGroups;
+      extraGroups = lib.optionals (options.admin or false) adminGroups;
+      inherit uid;
     };
 
-      javalsai = {
-        isNormalUser = true;
-        shell = pkgs.zsh;
-        extraGroups = adminGroups;
+    systemd.slices."user-${builtins.toString uid}".sliceConfig = {
+      CPUQuota = "50%";
+      CPUWeight = "10";
+      IOAccounting = true;
+      IOWeight = "10";
+      MemoryMax = "2G";
+      MemorySwapMax = "1G";
+      TasksMax = "100";
     };
   };
-}
+in
+(builtins.foldl'
+  (attrs: user: {
+    options = lib.recursiveUpdate attrs.options (mkUser user.name attrs.uid (user.options or { }));
+    uid = attrs.uid + 1;
+  })
+  {
+    options = { };
+    uid = 1000;
+  }
+  [
+    {
+      name = "error";
+      options.admin = true;
+    }
+    {
+      name = "javalsai";
+      options.admin = true;
+    }
+    {
+      name = "max";
+      options.admin = true;
+    }
+    {
+      name = "vectorum";
+    }
+  ]
+).options