add provider try catch, minor refactor

merino/providers/manifest/backends/protocol.py

@@ -52,8 +52,10 @@ async def fetch(self) -> tuple[GetManifestResultCode, ManifestData | None]:
         ...
 
     async def fetch_via_async_gcs_client(self) -> ManifestData | None:
-        """Use an async GCS client to fetch the manifest from storage and return it as a tuple.
+        """Use an async GCS client to fetch the manifest from bucket.
         Returns:
-            A tuple of (GetManifestResultCode, dict or None)
+            ManifestData or None
+        Raises:
+            RuntimeError: If the async storage client fails to initialize
         """
         ...

merino/providers/manifest/provider.py

@@ -89,4 +89,11 @@ def get_manifest_data(self) -> ManifestData | None:
 
     async def get_manifest_data_via_async_client(self) -> ManifestData | None:
         """Return manifest data"""
-        return await self.backend.fetch_via_async_gcs_client()
+        manifest_via_async = None
+
+        try:
+            manifest_via_async = await self.backend.fetch_via_async_gcs_client()
+        except Exception:
+            # We don't want our provider to blow up in case a RuntimeError is thrown by async_gcs_client module
+            return None
+        return manifest_via_async

merino/utils/gcs/async_gcs_client.py

@@ -38,11 +38,8 @@ async def get_manifest_from_blob(
             logger.error(f"Unexpected error when downloading blob: {ex}")
             return manifest
 
-        await self.close_client()
+        # close the client connection
+        await self.storage.close()
 
         logger.info("Succussfully downloaded manifest blob via async client")
         return manifest
-
-    async def close_client(self) -> None:
-        """Close the async client"""
-        await self.storage.close()