only update records and notify if IP has changed

route53_update.py

@@ -36,7 +36,26 @@ def _get_route53_client() -> Route53Client:
     return boto3.client("route53")
 
 
-def update_ipv4(hosted_zone_id: str, record: str, public_ipv4: str) -> None:
+def _get_current_record(hosted_zone_id: str, record: str, record_type: str) -> str | None:
+    client = _get_route53_client()
+    try:
+        response = client.list_resource_record_sets(HostedZoneId=hosted_zone_id)
+        record_normalized = record.rstrip(".")
+        for rrset in response["ResourceRecordSets"]:
+            if rrset["Name"].rstrip(".") == record_normalized and rrset["Type"] == record_type:
+                records = rrset.get("ResourceRecords", [])
+                if records:
+                    return records[0]["Value"].rstrip(".")
+    except Exception as e:
+        logger.warning("Failed to get current %s record for %s: %s", record_type, record, e)
+    return None
+
+
+def update_ipv4(hosted_zone_id: str, record: str, public_ipv4: str) -> bool:
+    current = _get_current_record(hosted_zone_id, record, "A")
+    if current == public_ipv4:
+        logger.info("IPv4 for %s is already %s, no update needed", record, public_ipv4)
+        return False
     logger.debug("Creating Route53 client for hosted zone %s", hosted_zone_id)
     client: Route53Client = _get_route53_client()
     logger.debug("Building ChangeBatch for IPv4: record=%s, ip=%s, ttl=300", record, public_ipv4)
@@ -60,12 +79,17 @@ def update_ipv4(hosted_zone_id: str, record: str, public_ipv4: str) -> None:
             },
         )
         logger.info("Successfully updated IPv4 for %s -> %s", record, public_ipv4)
+        return True
     except Exception as e:
         logger.error("Error updating IPv4 for %s: %s", record, e)
         raise e
 
 
-def update_ipv6(hosted_zone_id: str, record: str, public_ipv6: str) -> None:
+def update_ipv6(hosted_zone_id: str, record: str, public_ipv6: str) -> bool:
+    current = _get_current_record(hosted_zone_id, record, "AAAA")
+    if current == public_ipv6:
+        logger.info("IPv6 for %s is already %s, no update needed", record, public_ipv6)
+        return False
     logger.debug("Creating Route53 client for hosted zone %s", hosted_zone_id)
     client = _get_route53_client()
     logger.debug("Building ChangeBatch for IPv6: record=%s, ip=%s, ttl=300", record, public_ipv6)
@@ -89,6 +113,7 @@ def update_ipv6(hosted_zone_id: str, record: str, public_ipv6: str) -> None:
             },
         )
         logger.info("Successfully updated IPv6 for %s -> %s", record, public_ipv6)
+        return True
     except Exception as e:
         logger.error("Error updating IPv6 for %s: %s", record, e)
         raise e