Add some additional caching and logs to the robot cleanup migration

util/migrate/cleanup_old_robots.py

@@ -1,22 +1,39 @@
+import logging
+
 from data.database import User
 from util.names import parse_robot_username
 
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.INFO)
+
+
 def cleanup_old_robots(page_size=50):
   """ Deletes any robots that live under namespaces that no longer exist. """
   # Collect the robot accounts to delete.
   page_number = 1
   to_delete = []
+  encountered_namespaces = {}
 
   while True:
     found_bots = False
     for robot in list(User.select().where(User.robot == True).paginate(page_number, page_size)):
       found_bots = True
+      logger.info("Checking robot %s (page %s)", robot.username, page_number)
       namespace, _ = parse_robot_username(robot.username)
-      try:
-        User.get(username=namespace)
-      except User.DoesNotExist:
-        # Save the robot account for deletion.
-        to_delete.append(robot)
+
+      if namespace in encountered_namespaces:
+        if not encountered_namespaces[namespace]:
+          logger.info('Marking %s to be deleted', robot.username)
+          to_delete.append(robot)
+      else:
+        try:
+          User.get(username=namespace)
+          encountered_namespaces[namespace] = True
+        except User.DoesNotExist:
+          # Save the robot account for deletion.
+          logger.info('Marking %s to be deleted', robot.username)
+          to_delete.append(robot)
+          encountered_namespaces[namespace] = False
 
     if not found_bots:
       break
@@ -24,5 +41,7 @@ def cleanup_old_robots(page_size=50):
     page_number = page_number + 1
 
   # Cleanup any robot accounts whose corresponding namespace doesn't exist.
-  for robot in to_delete:
+  logger.info('Found %s robots to delete', len(to_delete))
+  for index, robot in enumerate(to_delete):
+    logger.info('Deleting robot %s of %s (%s)', index, len(to_delete), robot.username)
     robot.delete_instance(recursive=True, delete_nullable=True)