watch over grpc-gateway

[heyitsanthony]

(via #etcd)

Try:

curl localhost:2379/v3alpha/watch -d '{"request_union": {"create_request": {"key": "Zm9v"}}}}'

but get:

{"Error":"json: cannot unmarshal object into Go value of type etcdserverpb.isWatchRequest_RequestUnion","Code":2}

I attempted to figure out the correct syntax via encoding with grpc-gateway:

var protoReq WatchRequest                                                            
err = dec.Decode(&protoReq)                                                          
if err != nil {
    protoReq.RequestUnion = &WatchRequest_CreateRequest{ CreateRequest : &WatchCreateRequest{Key : []byte("abc") }}
    buf := new(bytes.Buffer)                                                     
    enc := marshaler.NewEncoder(buf)                                             
    err2 := enc.Encode(protoReq)                                                 
    b := buf.String()
    grpclog.Printf("Failed to decode request: %v \"%s\" %v", err, string(b), err2)    

Getting a potential JSON encoding back:

v3rpc/grpc: Failed to decode request: json: cannot unmarshal object into Go value of type etcdserverpb.isWatchRequest_RequestUnion "{"RequestUnion":{"CreateRequest":{"key":"YWJj"}}}" <nil>

Naturally, I try the value from Encode(protoReq), foolishly expecting Decode(Encode(x)) to work:

curl localhost:2379/v3alpha/watch -d '{"RequestUnion":{"CreateRequest":{"key":"YWJj"}}}'

but still an error:

{"Error":"unknown field \"RequestUnion\" in etcdserverpb.WatchRequest","Code":2}

[gyuho]

Yeah this is not working in my machine as well.

curl -L http://localhost:2379/v3alpha/watch -X POST -d '{"request_union": {"create_request": {"key": "Zm9v"}}}}'

I tried to tag the WatchRequest manually, like:

type WatchRequest struct {
    // request_union is a request to either create a new watcher or cancel an existing watcher.
    //
    // Types that are valid to be assigned to RequestUnion:
    //  *WatchRequest_CreateRequest
    //  *WatchRequest_CancelRequest
    RequestUnion isWatchRequest_RequestUnion `protobuf:"varint,3,opt,name=request_union,proto3" json:"request_union,omitempty protobuf_oneof:"request_union""`
}

but still doesn't work.

And I think upstream is aware of this issue here grpc-ecosystem/grpc-gateway#82.