nixos/tmp: move /tmp options under boot.tmp

nixos/modules/installer/tools/nixos-generate-config.pl

···
     }
 
     # Don't emit tmpfs entry for /tmp, because it most likely comes from the
-    # boot.tmpOnTmpfs option in configuration.nix (managed declaratively).
+    # boot.tmp.useTmpfs option in configuration.nix (managed declaratively).
     next if ($mountPoint eq "/tmp" && $fsType eq "tmpfs");
 
     # Emit the filesystem.

nixos/modules/system/boot/tmp.nix

···
 with lib;
 
 let
-  cfg = config.boot;
+  cfg = config.boot.tmp;
 in
 {
-
-  ###### interface
+  imports = [
+    (mkRenamedOptionModule [ "boot" "cleanTmpDir" ] [ "boot" "tmp" "cleanOnBoot" ])
+    (mkRenamedOptionModule [ "boot" "tmpOnTmpfs" ] [ "boot" "tmp" "useTmpfs" ])
+    (mkRenamedOptionModule [ "boot" "tmpOnTmpfsSize" ] [ "boot" "tmp" "tmpfsSize" ])
+  ];
 
   options = {
+    boot.tmp = {
+      cleanOnBoot = mkOption {
+        type = types.bool;
+        default = false;
+        description = lib.mdDoc ''
+          Whether to delete all files in {file}`/tmp` during boot.
+        '';
+      };
 
-    boot.cleanTmpDir = mkOption {
-      type = types.bool;
-      default = false;
-      description = lib.mdDoc ''
-        Whether to delete all files in {file}`/tmp` during boot.
-      '';
-    };
-
-    boot.tmpOnTmpfs = mkOption {
-      type = types.bool;
-      default = false;
-      description = lib.mdDoc ''
-         Whether to mount a tmpfs on {file}`/tmp` during boot.
-      '';
-    };
+      tmpfsSize = mkOption {
+        type = types.oneOf [ types.str types.types.ints.positive ];
+        default = "50%";
+        description = lib.mdDoc ''
+          Size of tmpfs in percentage.
+          Percentage is defined by systemd.
+        '';
+      };
 
-    boot.tmpOnTmpfsSize = mkOption {
-      type = types.oneOf [ types.str types.types.ints.positive ];
-      default = "50%";
-      description = lib.mdDoc ''
-        Size of tmpfs in percentage.
-        Percentage is defined by systemd.
-      '';
+      useTmpfs = mkOption {
+        type = types.bool;
+        default = false;
+        description = lib.mdDoc ''
+           Whether to mount a tmpfs on {file}`/tmp` during boot.
+        '';
+      };
     };
-
   };
-
-  ###### implementation
 
   config = {
-
     # When changing remember to update /tmp mount in virtualisation/qemu-vm.nix
-    systemd.mounts = mkIf cfg.tmpOnTmpfs [
+    systemd.mounts = mkIf cfg.useTmpfs [
       {
         what = "tmpfs";
         where = "/tmp";
         type = "tmpfs";
-        mountConfig.Options = concatStringsSep "," [ "mode=1777"
-                                                     "strictatime"
-                                                     "rw"
-                                                     "nosuid"
-                                                     "nodev"
-                                                     "size=${toString cfg.tmpOnTmpfsSize}" ];
+        mountConfig.Options = concatStringsSep "," [
+          "mode=1777"
+          "strictatime"
+          "rw"
+          "nosuid"
+          "nodev"
+          "size=${toString cfg.tmpfsSize}"
+        ];
       }
     ];
 
-    systemd.tmpfiles.rules = optional config.boot.cleanTmpDir "D! /tmp 1777 root root";
-
+    systemd.tmpfiles.rules = optional cfg.cleanOnBoot "D! /tmp 1777 root root";
   };
-
 }

nixos/modules/virtualisation/qemu-vm.nix

···
           fsType = "ext4";
           autoFormat = true;
         });
-        "/tmp" = lib.mkIf config.boot.tmpOnTmpfs {
+        "/tmp" = lib.mkIf config.boot.tmp.useTmpfs {
           device = "tmpfs";
           fsType = "tmpfs";
           neededForBoot = true;
           # Sync with systemd's tmp.mount;
-          options = [ "mode=1777" "strictatime" "nosuid" "nodev" "size=${toString config.boot.tmpOnTmpfsSize}" ];
+          options = [ "mode=1777" "strictatime" "nosuid" "nodev" "size=${toString config.boot.tmp.tmpfsSize}" ];
         };
         "/nix/${if cfg.writableStore then ".ro-store" else "store"}" = lib.mkIf cfg.useNixStoreImage {
           device = "${lookupDriveDeviceName "nix-store" cfg.qemu.drives}";

nixos/tests/ihatemoney/default.nix

···
           http = ":8000";
         };
       };
-      boot.cleanTmpDir = true;
+      boot.tmp.cleanOnBoot = true;
       # for exchange rates
       security.pki.certificateFiles = [ ./server.crt ];
       networking.extraHosts = "127.0.0.1 api.exchangerate.host";