Merge ~twom/launchpad:reraise-after-failed-retry into launchpad:master

[Tom Wardill]

Reraise the original error on a failed retry

We are using tenacity to retry ConnectionErrors in OCI Registry Uploads.
By default if this fails all the retries, you get a RetryError raised.

Instead, lets raise the original ConnectionError as it'll give us more diagnostics.

[Colin Watson (cjwatson)]

review: Approve

diff --git a/lib/lp/oci/model/ociregistryclient.py b/lib/lp/oci/model/ociregistryclient.py
index dbed50c..98b925e 100644
--- a/lib/lp/oci/model/ociregistryclient.py
+++ b/lib/lp/oci/model/ociregistryclient.py
@@ -102,6 +102,7 @@ class OCIRegistryClient:
     @retry(
         wait=wait_fixed(3),
         before=before_log(log, logging.INFO),
+        reraise=True,
         retry=retry_if_exception_type(ConnectionError),
         stop=stop_after_attempt(5))
     def _upload(cls, digest, push_rule, fileobj, length, http_client):
diff --git a/lib/lp/oci/tests/test_ociregistryclient.py b/lib/lp/oci/tests/test_ociregistryclient.py
index 2fa179e..286bdce 100644
--- a/lib/lp/oci/tests/test_ociregistryclient.py
+++ b/lib/lp/oci/tests/test_ociregistryclient.py
@@ -535,12 +535,14 @@ class TestOCIRegistryClient(OCIConfigHelperMixin, SpyProxyCallsMixin,
             self.client._upload(
                 "test-digest", push_rule,
                 None, 0, RegistryHTTPClient(push_rule))
-        except RetryError:
-            pass
-        # Check that tenacity and our counting agree
-        self.assertEqual(
-            5, self.client._upload.retry.statistics["attempt_number"])
-        self.assertEqual(5, self.retry_count)
+        except ConnectionError:
+            # Check that tenacity and our counting agree
+            self.assertEqual(
+                5, self.client._upload.retry.statistics["attempt_number"])
+            self.assertEqual(5, self.retry_count)
+        except Exception:
+            # We should see the original exception, not a RetryError
+            raise
 
     @responses.activate
     def test_upload_put_blob_raises_error(self):