many changes and more modularizing

hosts/fw-new/modules/update-containers.nix

@@ -0,0 +1,39 @@
+{ config, pkgs, ... }:
+let
+  update-containers = pkgs.writeShellScriptBin "update-containers" ''
+    SUDO=""
+    if [[ $(id -u) -ne 0 ]]; then
+      SUDO="sudo"
+    fi
+
+      images=$($SUDO ${pkgs.podman}/bin/podman ps -a --format="{{.Image}}" | sort -u)
+
+      for image in $images
+      do
+        $SUDO ${pkgs.podman}/bin/podman pull $image
+      done
+  '';
+in {
+  systemd.timers = {
+    # ...
+    updatecontainers = {
+      timerConfig = {
+        Unit = "updatecontainers.service";
+        OnCalendar = "02:00";
+      };
+      wantedBy = [ "timers.target" ];
+    };
+    # ...
+  };
+
+  systemd.services = {
+    # ...
+    updatecontainers = {
+      serviceConfig = {
+        Type = "oneshot";
+        ExecStart = "update-containers";
+      };
+    };
+    # ...
+  };
+}