fix: retry token on error (#16957)

tests/unit/helpdesk/test_services.py

@@ -19,6 +19,7 @@
 import requests
 import responses
 
+from pyramid_retry import RetryableException
 from zope.interface.verify import verifyClass
 
 from warehouse.helpdesk.interfaces import IHelpDeskService
@@ -101,6 +102,28 @@ def test_create_service_fails_when_missing_setting(self, partial_setting):
         with pytest.raises(KeyError):
             HelpScoutService.create_service(context, request)
 
+    @responses.activate
+    def test_retries_on_error(self):
+        responses.add(
+            responses.POST,
+            "https://api.helpscout.net/v2/oauth2/token",
+            body=requests.exceptions.RequestException(),
+        )
+
+        context = None
+        request = pretend.stub(
+            http=requests.Session(),
+            registry=pretend.stub(
+                settings={
+                    "helpscout.app_id": "an insecure helpscout app id",
+                    "helpscout.app_secret": "an insecure helpscout app secret",
+                },
+            ),
+        )
+
+        with pytest.raises(RetryableException):
+            HelpScoutService.create_service(context, request)
+
     @responses.activate
     def test_create_conversation(self):
         responses.add(

warehouse/helpdesk/services.py

@@ -21,6 +21,8 @@
 
 from textwrap import dedent
 
+from pyramid_retry import RetryableException
+from requests.exceptions import RequestException
 from zope.interface import implementer
 
 from .interfaces import IHelpDeskService
@@ -93,15 +95,18 @@ def create_service(cls, _context, request: Request) -> HelpScoutService:
         #
         # TODO: Ideally, we would cache this token for up to 48 hours and reuse it.
         #  For now, we'll just get a new token each time, since we're low enough volume.
-        resp = request.http.post(
-            "https://api.helpscout.net/v2/oauth2/token",
-            json={
-                "grant_type": "client_credentials",
-                "client_id": _app_id,
-                "client_secret": _app_secret,
-            },
-        )
-        resp.raise_for_status()
+        try:
+            resp = request.http.post(
+                "https://api.helpscout.net/v2/oauth2/token",
+                json={
+                    "grant_type": "client_credentials",
+                    "client_id": _app_id,
+                    "client_secret": _app_secret,
+                },
+            )
+            resp.raise_for_status()
+        except RequestException as e:
+            raise RetryableException from e
 
         return cls(
             session=request.http,