fix(prompt_client): gracefully handle invalid CRE_LLM_* env vars (#1169)

application/prompt_client/litellm_router.py

@@ -21,12 +21,38 @@
 LlmFn = Callable[[str, str], str]
 
 
+DEFAULT_MAX_RETRIES = 2
+DEFAULT_RETRY_SLEEP_SECONDS = 15
+
+
 def retry_policy() -> tuple[int, int]:
-    """Return (max_retries, sleep_seconds) from CRE_LLM_* env vars."""
-    return (
-        int(os.environ.get("CRE_LLM_MAX_RETRIES", "2")),
-        int(os.environ.get("CRE_LLM_RETRY_SLEEP_SECONDS", "15")),
-    )
+    """Return (max_retries, sleep_seconds) from CRE_LLM_* env vars with defensive fallback."""
+    raw_retries = os.environ.get("CRE_LLM_MAX_RETRIES")
+    raw_sleep = os.environ.get("CRE_LLM_RETRY_SLEEP_SECONDS")
+
+    max_retries = DEFAULT_MAX_RETRIES
+    if raw_retries is not None:
+        try:
+            max_retries = max(0, int(raw_retries.strip()))
+        except (ValueError, AttributeError):
+            logger.warning(
+                "Invalid CRE_LLM_MAX_RETRIES=%r; falling back to default %d",
+                raw_retries,
+                DEFAULT_MAX_RETRIES,
+            )
+
+    sleep_seconds = DEFAULT_RETRY_SLEEP_SECONDS
+    if raw_sleep is not None:
+        try:
+            sleep_seconds = max(0, int(raw_sleep.strip()))
+        except (ValueError, AttributeError):
+            logger.warning(
+                "Invalid CRE_LLM_RETRY_SLEEP_SECONDS=%r; falling back to default %d",
+                raw_sleep,
+                DEFAULT_RETRY_SLEEP_SECONDS,
+            )
+
+    return (max_retries, sleep_seconds)
 
 
 def get_litellm() -> Any:

application/tests/litellm_router_test.py

@@ -83,6 +83,45 @@ def test_extract_content_text_lenient_on_empty(self) -> None:
             "",
         )
 
+    def test_retry_policy_defaults(self) -> None:
+        with patch.dict(os.environ, {}, clear=True):
+            retries, sleep = litellm_router.retry_policy()
+            self.assertEqual(retries, 2)
+            self.assertEqual(sleep, 15)
+
+    def test_retry_policy_valid_env(self) -> None:
+        with patch.dict(
+            os.environ,
+            {"CRE_LLM_MAX_RETRIES": "5", "CRE_LLM_RETRY_SLEEP_SECONDS": "20"},
+            clear=True,
+        ):
+            retries, sleep = litellm_router.retry_policy()
+            self.assertEqual(retries, 5)
+            self.assertEqual(sleep, 20)
+
+    def test_retry_policy_invalid_strings_fallback(self) -> None:
+        with patch.dict(
+            os.environ,
+            {"CRE_LLM_MAX_RETRIES": "invalid", "CRE_LLM_RETRY_SLEEP_SECONDS": "not-a-number"},
+            clear=True,
+        ):
+            with self.assertLogs("application.prompt_client.litellm_router", level="WARNING") as cm:
+                retries, sleep = litellm_router.retry_policy()
+            self.assertEqual(retries, 2)
+            self.assertEqual(sleep, 15)
+            self.assertTrue(any("Invalid CRE_LLM_MAX_RETRIES" in log for log in cm.output))
+            self.assertTrue(any("Invalid CRE_LLM_RETRY_SLEEP_SECONDS" in log for log in cm.output))
+
+    def test_retry_policy_negative_values_clamped(self) -> None:
+        with patch.dict(
+            os.environ,
+            {"CRE_LLM_MAX_RETRIES": "-2", "CRE_LLM_RETRY_SLEEP_SECONDS": "-10"},
+            clear=True,
+        ):
+            retries, sleep = litellm_router.retry_policy()
+            self.assertEqual(retries, 0)
+            self.assertEqual(sleep, 0)
+
 
 if __name__ == "__main__":
     unittest.main()