playlist_manager: Add --once option

playlist_manager/playlist_manager/main.py

@@ -437,6 +437,7 @@ def main(
 	playlists,
 	upload_location_allowlist="youtube",
 	interval=600,
+	once=False,
 	metrics_port=8007,
 	backdoor_port=0,
 ):
@@ -452,6 +453,7 @@ def main(
 	upload_location.
 
 	interval is how often to check for new videos, default every 10min.
+	If --once is given, interval is ignored and we exit after one check.
 	"""
 	common.PromLogCountsHandler.install()
 	common.install_stacksampler()
@@ -475,6 +477,9 @@ def main(
 	dbmanager = DBManager(dsn=dbconnect)
 	manager = PlaylistManager(dbmanager, client, upload_locations, playlists)
 
+	if once:
+		manager.run_once()
+	else:
 		while not stop.is_set():
 			try:
 				manager.run_once()