feat(client): automatically retry on HTTP 409 Resource lock

pspacek · pspacek · commit fdb1d2ccf154 · 2022-10-18T14:51:11.000+02:00
Fixes: #2325
diff --git a/docs/api-usage-advanced.rst b/docs/api-usage-advanced.rst
@@ -123,9 +123,11 @@ GitLab server can sometimes return a transient HTTP error.
 python-gitlab can automatically retry in such case, when
 ``retry_transient_errors`` argument is set to ``True``.  When enabled,
 HTTP error codes 500 (Internal Server Error), 502 (502 Bad Gateway),
-503 (Service Unavailable), and 504 (Gateway Timeout) are retried. It will retry until reaching
-the ``max_retries`` value. By default, ``retry_transient_errors`` is set to ``False`` and an exception
-is raised for these errors.
+503 (Service Unavailable), and 504 (Gateway Timeout) are retried.
+Additionally the HTTP error code 409 (Conflict) is retried if the text message
+mentions "Resource lock". It will retry until reaching the ``max_retries``
+value. By default, ``retry_transient_errors`` is set to ``False`` and an
+exception is raised for these errors.
 
 .. code-block:: python
 
diff --git a/gitlab/client.py b/gitlab/client.py
@@ -764,7 +764,10 @@ def http_request(
                 return result
 
             if (429 == result.status_code and obey_rate_limit) or (
-                result.status_code in RETRYABLE_TRANSIENT_ERROR_CODES
+                (
+                    result.status_code in RETRYABLE_TRANSIENT_ERROR_CODES
+                    or (result.status_code == 409 and "Resource lock" in result.reason)
+                )
                 and retry_transient_errors
             ):
                 # Response headers documentation:
