1 files changed, 83 insertions, 0 deletions
diff --git a/modules/system/users.nix b/modules/system/users.nix
new file mode 100644
index 0000000..022a7e7
--- /dev/null
+++ b/modules/system/users.nix
@@ -0,0 +1,83 @@
+{ config, pkgs, lib, ... }:
+
+let
+
+  inherit (builtins)
+    genList hashString mul substring ;
+
+  inherit (lib)
+    foldl genAttrs imap mkOption stringToCharacters toLower
+    types unique ;
+
+  inherit (types)
+    listOf str ;
+
+  uid = name:
+    let
+      dec = {
+        "0" =  0; "1" =  1; "2" =  2; "3" =  3;
+        "4" =  4; "5" =  5; "6" =  6; "7" =  7;
+        "8" =  8; "9" =  9; "a" = 10; "b" = 11;
+        "c" = 12; "d" = 13; "e" = 14; "f" = 15;
+      };
+      base = 1000000000; # 2^32 > base + 16^7
+      hex = toLower (substring 0 7 (hashString "sha1" name));
+      pow = b: n: foldl mul 1 (genList (_: b) n);
+      digits = imap (i: d: {m = pow 16 (i - 1); d = d;}) (stringToCharacters hex);
+      f = a: {m, d}: a + m * dec.${d};
+
+    in foldl f base digits;
+
+  daemons = config.nixsap.system.users.daemons;
+  normal = config.nixsap.system.users.normal;
+  groups = config.nixsap.system.groups;
+
+  mkGroup = name: { gid = uid name; };
+  mkDaemonUser = name:
+    {
+      isNormalUser = false;
+      uid = uid name;
+      group = name;
+    };
+
+  mkNormalUser = name:
+    {
+      isNormalUser = true;
+      uid = uid name;
+    };
+
+in {
+  options.nixsap.system = {
+    users.daemons = mkOption {
+      type = listOf str;
+      description = "List of system users with automatic UID and group";
+      default = [];
+    };
+    users.normal = mkOption {
+      type = listOf str;
+      description = "List of regular users with automatic UID";
+      default = [];
+    };
+    users.sysops = mkOption {
+      description = ''
+        List of local users with special roles in applications or system-wide.
+        The users in this list are not create automatically.
+      '';
+      type = listOf str;
+      default = [];
+    };
+    groups = mkOption {
+      type = listOf str;
+      description = "List of groups with automatic GID";
+      default = [];
+    };
+  };
+
+  # XXX: Modules for automatic unicity of user names:
+  imports = [
+    { users.groups = genAttrs (unique (daemons ++ groups)) mkGroup; }
+    { users.users = genAttrs daemons mkDaemonUser; }
+    { users.users = genAttrs normal mkNormalUser; }
+  ];
+}
+