Optimized udev rules for backup to usb with the help of chat gpt https://chat.openai.com/share/a75ca771-d8a4-4b75-9912-c515ba371ae4

roles/independent_backup-to-usb/templates/99-usbstick.rules.j2

@@ -0,0 +1 @@
+ACTION=="add", SUBSYSTEM=="block", ENV{ID_SERIAL_SHORT}=="{{ backup_to_usb_serial_short }}", RUN+="/usr/bin/systemd-mount --no-block $devnode {{ mount_point }}", SYMLINK+="backup_usb"

roles/independent_backup-to-usb/templates/backup-to-usb.service.j2

@@ -0,0 +1,10 @@
+[Unit]
+Description=Backup to USB when it's plugged in
+After=local-fs.target
+OnFailure=systemd-email@%n.service
+
+[Service]
+ExecStart={{ backup_to_usb_script_path }} {{ mount_point }}/{{ backup_to_usb_subdirectory }} {{ backup_to_usb_source_path }}
+
+[Install]
+WantedBy=multi-user.target

roles/independent_backup-to-usb/templates/backup-to-usb.sh.j2

@@ -0,0 +1,35 @@
+#!/bin/sh
+backup_to_usb_destination_path="{{ mount_point }}" &&
+echo "backup to usb destination path: $backup_to_usb_destination_path" &&
+
+source_path="{{ backup_to_usb_source_path }}" &&
+echo "source path: $source_path" || exit 1
+
+if [ ! -d "$backup_to_usb_destination_path" ]; then
+    echo "Directory $backup_to_usb_destination_path does not exist" &&
+    exit 1
+fi
+
+machine_id="$(sha256sum /etc/machine-id | head -c 64 )" &&
+echo "machine id: $machine_id" &&
+
+versions_path="$backup_to_usb_destination_path$machine_id/backup-to-usb/" &&
+echo "versions path: $versions_path" || exit 1
+
+if [ ! -d "$versions_path" ]; then
+    echo "Creating $versions_path..." &&
+    mkdir -vp $versions_path || exit 1
+fi 
+
+previous_version_path="$(ls -d $versions_path* | tail -1)" &&
+echo "previous versions path: $previous_version_path" &&
+
+current_version_path="$versions_path$(date '+%Y%m%d%H%M%S')" &&
+echo "current versions path: $current_version_path" &&
+
+echo "creating backup destination folder..." &&
+mkdir -vp "$current_version_path" &&
+
+echo "Starting synchronization..."
+rsync -abP --delete --delete-excluded --link-dest="$previous_version_path" "$source_path" "$current_version_path" &&
+echo "Synchronization finished." || exit 1