Prune backups

roles/backup/templates/s3backup.sh

@@ -54,9 +54,26 @@ backup() {
 		for dir in "$@"; do
 			echo "- $dir"
 		done
+		# Back up everything in the $DIRS array (which was passed as args)
 		/opt/restic-wrapper \
 			backup \
 			"$@"
+		# In addition, we should also prune our backups
+		# https://restic.readthedocs.io/en/stable/060_forget.html
+		# --keep-daily n	Keeps daily backups for the last n days
+		# --keep-weekly n	Keeps weekly backups for the last n weeks
+		# --keep-montly n	Keeps monthly backups for the last n months
+		# --keep-tag foo	Keeps all snapshots tagged with "foo"
+		# --host "$HOSTNAME"	Only act on *our* snapshots. We don't care about other machines'
+		# --prune		Remove orphaned blobs when we remove snapshots
+		/opt/restic-wrapper \
+			forget \
+			--keep-daily 7 \
+			--keep-weekly 4 \
+			--keep-monthly 6 \
+			--keep-tag noremove \
+			--host "$HOSTNAME" \
+			--prune
 	else
 		dir="$@"
 		echo "- $dir"