Cleanup: use max of last update and start time to determine expiry time

src/ddns_service/cleanup.py

@@ -8,12 +8,13 @@ from .models import Hostname, User
 from datetime import timedelta
 
 
-def cleanup_expired(app):
+def cleanup_expired(app, start_time=None):
     """
     Clean up expired hostnames and return count of cleaned entries.
 
     Args:
         app: Application instance with dns_service and email_service.
+        start_time: Timezone aware datetime object containg the start time of the cleanup thread.
 
     Returns:
         Number of expired hostnames processed.
@@ -30,12 +31,14 @@ def cleanup_expired(app):
         ipv6_expired = False
 
         if hostname.last_ipv4:
-            expiry_time = hostname.last_ipv4_update + timedelta(seconds=hostname.expiry_ttl)
+            last_update = max(hostname.last_ipv4_update, start_time)
+            expiry_time = last_update + timedelta(seconds=hostname.expiry_ttl)
             if now > expiry_time:
                 ipv4_expired = True
 
         if hostname.last_ipv6:
-            expiry_time = hostname.last_ipv6_update + timedelta(seconds=hostname.expiry_ttl)
+            last_update = max(hostname.last_ipv6_update, start_time)
+            expiry_time = last_update + timedelta(seconds=hostname.expiry_ttl)
             if now > expiry_time:
                 ipv6_expired = True
 
@@ -117,10 +120,11 @@ class ExpiredRecordsCleanupThread(threading.Thread):
     def run(self):
         """Run the cleanup loop."""
         logging.info(f"Expired records cleanup thread started: interval={self.interval}s")
+        start_time = now_utc()
 
         while not self.stop_event.wait(self.interval):
             try:
-                count = cleanup_expired(self.app)
+                count = cleanup_expired(self.app, start_time)
                 if count > 0:
                     logging.info(f"Expired records cleanup completed: count={count}")
             except Exception as e: