From e8f8610c5bcfffceafaf051823ddaf9079668cd3 Mon Sep 17 00:00:00 2001
From: fullsend-code
 <278716306+fullsend-ai-coder[bot]@users.noreply.github.com>
Date: Fri, 14 Aug 2026 12:05:26 +0000
Subject: [PATCH] feat(#3164): add retry on 5xx for Testing Farm API calls

Replace the plain integer max_retries=5 on the HTTPAdapter with a
proper urllib3 Retry strategy that retries on HTTP 500, 502, 503,
and 504 status codes with exponential backoff (backoff_factor=1).
The previous configuration only retried transport-level connection
errors, not server-side HTTP error responses.

The retry strategy explicitly allows GET, POST, and DELETE methods
so that TF request submission and cancellation are also retried.

Closes #3164
---
 .../worker/helpers/testing_farm_client.py     | 12 +++++-
 tests/unit/test_testing_farm.py               | 43 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/packit_service/worker/helpers/testing_farm_client.py b/packit_service/worker/helpers/testing_farm_client.py
index cca204e95..61cddd56b 100644
--- a/packit_service/worker/helpers/testing_farm_client.py
+++ b/packit_service/worker/helpers/testing_farm_client.py
@@ -11,6 +11,7 @@
 from ogr.utils import RequestResponse
 from packit.constants import HTTP_REQUEST_TIMEOUT
 from packit.exceptions import PackitException
+from urllib3.util.retry import Retry
 
 from packit_service.config import ServiceConfig
 from packit_service.constants import (
@@ -33,7 +34,16 @@ def __init__(self, api_url: str, token: str, use_internal_tf: bool = False) -> N
         self._token = token
 
         self.session = requests.session()
-        self.session.mount("https://", requests.adapters.HTTPAdapter(max_retries=5))
+        retry_strategy = Retry(
+            total=5,
+            backoff_factor=1,
+            status_forcelist=[500, 502, 503, 504],
+            allowed_methods=["GET", "POST", "DELETE"],
+        )
+        self.session.mount(
+            "https://",
+            requests.adapters.HTTPAdapter(max_retries=retry_strategy),
+        )
         self.session.headers.update({"Authorization": f"Bearer {self._token}"})
 
     @property
diff --git a/tests/unit/test_testing_farm.py b/tests/unit/test_testing_farm.py
index ec3610e4a..d59b69b0c 100644
--- a/tests/unit/test_testing_farm.py
+++ b/tests/unit/test_testing_farm.py
@@ -2480,3 +2480,46 @@ def test_empty_development_list(self):
             {"fedora-development": []},
         )
         assert TFJobHelper.is_freshly_branched_fedora("fedora-42") is False
+
+
+class TestTestingFarmClientRetry:
+    """Tests for the retry mechanism configured on the TF API client."""
+
+    def test_retry_strategy_is_configured(self):
+        """Verify that the session retry strategy retries on 5xx status codes."""
+        from urllib3.util.retry import Retry
+
+        service_config = ServiceConfig.get_service_config()
+        client = TFClient(
+            api_url=service_config.testing_farm_api_url,
+            token=service_config.testing_farm_secret,
+        )
+        adapter = client.session.get_adapter("https://example.com")
+        retry = adapter.max_retries
+
+        assert isinstance(retry, Retry)
+        assert retry.total == 5
+        assert retry.backoff_factor == 1
+        assert 500 in retry.status_forcelist
+        assert 502 in retry.status_forcelist
+        assert 503 in retry.status_forcelist
+        assert 504 in retry.status_forcelist
+
+    def test_retry_allows_post_and_delete(self):
+        """Verify that POST and DELETE methods are retried (needed for TF
+        request submission and cancellation)."""
+        from urllib3.util.retry import Retry
+
+        service_config = ServiceConfig.get_service_config()
+        client = TFClient(
+            api_url=service_config.testing_farm_api_url,
+            token=service_config.testing_farm_secret,
+        )
+        adapter = client.session.get_adapter("https://example.com")
+        retry = adapter.max_retries
+
+        assert isinstance(retry, Retry)
+        allowed = retry.allowed_methods
+        assert "GET" in allowed
+        assert "POST" in allowed
+        assert "DELETE" in allowed