nixos/tmp: add tmpOnTmpfsSize

1 files changed, 15 insertions, 2 deletions

diff --git a/nixos/modules/system/boot/tmp.nix b/nixos/modules/system/boot/tmp.nix
index 5bb299adb15..6edafd6695b 100644
--- a/nixos/modules/system/boot/tmp.nix
+++ b/nixos/modules/system/boot/tmp.nix
@@ -2,6 +2,9 @@
 
 with lib;
 
+let
+  cfg = config.boot;
+in
 {
 
   ###### interface
@@ -24,18 +27,28 @@ with lib;
       '';
     };
 
+    boot.tmpOnTmpfsSize = mkOption {
+      type = types.oneOf [ types.str types.types.ints.positive ];
+      default = "50%";
+      description = ''
+        Size of tmpfs in percentage.
+        Percentage is defined by systemd.
+      '';
+    };
+
   };
 
   ###### implementation
 
   config = {
 
-    systemd.mounts = mkIf config.boot.tmpOnTmpfs [
+    # When changing remember to update /tmp mount in virtualisation/qemu-vm.nix
+    systemd.mounts = mkIf cfg.tmpOnTmpfs [
       {
         what = "tmpfs";
         where = "/tmp";
         type = "tmpfs";
-        mountConfig.Options = [ "mode=1777" "strictatime" "rw" "nosuid" "nodev" "size=50%" ];
+        mountConfig.Options = [ "mode=1777" "strictatime" "rw" "nosuid" "nodev" "size=${toString cfg.tmpOnTmpfsSize}" ];
       }
     ];