Why the trailer frame is needed for gRPC? Any luck on making it work with Amazon ALB?

[yz]

We tested gRPC on ALB for the past week, we have found out following facts:

```

1. ALB will translate HTTP2 to HTTP 1.1, with the protobuf translated into chunked-encoding request body. And this body can be decoded on the upstream server;

2. ALB end the stream with a data frame without adding a trailer header frame, which is the gRPC client expecting. So the Go client library will just throw an error.

```

From rfc7540, the trailer frame is not required, but it seems that the gRPC client requires it?

If so, is there a workaround for 2?

Thank you very much!

[Ken Payson]

gRPC Uses the trailer frame to send the status code, and is required.

Any HTTP2/HTTP1.1 translation will need a mechanism to include the status code in the trailer.