ServeHTTP should support HTTP2 / vanilla gRPC

[philipithomas]

It looks like the Serve HTTP does not currently support vanilla HTTP2 gRPC requests.

I propose changing the ServeHTTP to check defer to grpcServer.ServeHTTP when the request is HTTP2.

It should look something like this:

func (w *WrappedGrpcServer) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
	if r.ProtoMajor == 2 && strings.Contains(r.Header.Get("Content-Type"), "application/grpc") {
			w.grpcServer.ServeHTTP(w, r)
        } else if w.IsAcceptableGrpcCorsRequest(req) || w.IsGrpcWebRequest(req) {
		w.corsWrapper.Handler(http.HandlerFunc(w.HandleGrpcWebRequest)).ServeHTTP(resp, req)
		return
	}
	w.server.ServeHTTP(resp, req)
}

(source parent)

So - is this approach ok? If I code it, will it get merged?

[MarcusLongmuir]

@philipithomas: This makes sense. Can you open a PR please?

[johanbrandhorst]

This issue confuses me a little, as w.grpcServer is currently not a field on the wrapper? I was going to suggest something similar to this but instead changing the parameter to the WrapServer method to a http.Handler to make it more composable. The restriction on a *grpc.Server type means you can't chain handlers easily with the wrapper. I think this would solve both these problems by letting th user define this handling themselves, if they wish, and passing that handler into the wrapper.

[johanbrandhorst]

I've opened #81 which contains the suggested change.

[easyCZ]

Stale. Closing.

[frederikhors]

@MarcusLongmuir maybe we should reopen this?