Add cleanup thread, use systemd directories

objectifier-module.nix

@@ -35,6 +35,21 @@ in {
         "List of IP addresses on which to listen for incoming requests.";
       default = [ "127.0.0.1" ];
     };
+
+    cleanup = {
+      max_file_age = mkOption {
+        type = int;
+        description =
+          "Maximum age of a file (in seconds), after which it will be removed.";
+        default = 60 * 60 * 8; # 8 hours
+      };
+
+      delay = {
+        type = int;
+        description = "Time between cleanup sweeps.";
+        default = 60 * 10; # 10 minutes
+      };
+    };
   };
 
   config = mkIf cfg.enable {
@@ -48,6 +63,8 @@ in {
         OBJECTIFIER_YOLOV3_WEIGHTS = "${pkgs.yolov3-data}/yolov3.weights";
         OBJECTIFIER_YOLOV3_LABELS = "${pkgs.yolov3-data}/labels";
         OBJECTIFIER_BUFFER_SIZE = "524288";
+        OBJECTIFIER_CLEANUP_MAX_AGE = toString cfg.cleanup.max_file_age;
+        OBJECTIFIER_CLEANUP_DELAY = toString cfg.cleanup.delay;
       };
       serviceConfig = {
         # PrivateUsers = true;