use ssh key file

code/backup_rsync_git.env

@@ -1,5 +1,8 @@
 # Remote rsync source. Example: backup@example.com:/srv/data/project/
 RSYNC_SOURCE="boogie@eukelade.uberspace.de:/home/boogie/nextcloud_data/root/files/Obsidian"
+# SSH key file used by rsync/ssh
+SSH_KEY_FILE="/home/truenas_admin/.ssh/backup_rsync"
+
 
 # Local sync destination (must be a directory inside GIT_REPO_DIR)
 RSYNC_TARGET_DIR="/mnt/bfds-nix/rob/backup/Obsidian-daily-git/Obsidian"