SearchAPI - Index.get(doc_id) fails with 500 internal server error

[scragraham]

Summary
Search api document get() requests fail with a 500 internal server error

Unittest

class GetTest(SearchTestCase):

  def test_search_get(self):
    response = self.app.post(
      '/python/search/get',
      json={"index": "index-1", "id": "a"})
    self.assertEquals(response.status_code, 200)

Expected
Document: id: a

Actual
500 Internal Server error

Application Logs
This is the Hawkeye python application logs, looks like the protocol buffer is corrupted:

ERROR    2018-12-14 23:05:25,329 webapp2.py:1528] corrupted
Traceback (most recent call last):
  File "/root/appscale/AppServer/lib/webapp2-2.3/webapp2.py", line 1511, in __call__
    rv = self.handle_exception(request, response, e)
  File "/root/appscale/AppServer/lib/webapp2-2.3/webapp2.py", line 1505, in __call__
    rv = self.router.dispatch(request, response)
  File "/root/appscale/AppServer/lib/webapp2-2.3/webapp2.py", line 1253, in default_dispatcher
    return route.handler_adapter(request, response)
  File "/root/appscale/AppServer/lib/webapp2-2.3/webapp2.py", line 1077, in __call__
    return handler.dispatch()
  File "/root/appscale/AppServer/lib/webapp2-2.3/webapp2.py", line 547, in dispatch
    return self.handle_exception(e, self.app.debug)
  File "/root/appscale/AppServer/lib/webapp2-2.3/webapp2.py", line 545, in dispatch
    return method(*args, **kwargs)
  File "/var/apps/hawkeyepython27_default_v1_1544644216773/app/search.py", line 64, in post
    document = search.Index(name=index).get(doc_id)
  File "/root/appscale/AppServer/google/appengine/api/search/search.py", line 2642, in get
    response = self.get_range(start_id=doc_id, limit=1)
  File "/root/appscale/AppServer/google/appengine/api/search/search.py", line 2799, in get_range
    limit=limit, ids_only=ids_only, **kwargs)
  File "/root/appscale/AppServer/google/appengine/api/search/search.py", line 2770, in _GetResponse
    response)
  File "/root/appscale/AppServer/google/appengine/api/apiproxy_stub_map.py", line 94, in MakeSyncCall
    return stubmap.MakeSyncCall(service, call, request, response)
  File "/root/appscale/AppServer/google/appengine/api/apiproxy_stub_map.py", line 326, in MakeSyncCall
    rpc.CheckSuccess()
  File "/root/appscale/AppServer/google/appengine/api/apiproxy_rpc.py", line 234, in _make_sync_call
    self.stub.MakeSyncCall(service, call, request, response)
  File "/root/appscale/AppServer/google/appengine/ext/remote_api/remote_api_stub.py", line 201, in MakeSyncCall
    self._MakeRealSyncCall(service, call, request, response)
  File "/root/appscale/AppServer/google/appengine/ext/remote_api/remote_api_stub.py", line 238, in _MakeRealSyncCall
    raise pickle.loads(response_pb.exception())
ProtocolBufferDecodeError: corrupted