// NewServerHandlerTransport returns a ServerTransport handling gRPC
// from inside an http.Handler. It requires that the http Server
// supports HTTP/2.
func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request) (ServerTransport, error) {
if r.ProtoMajor != 2 {
return nil, errors.New("gRPC requires HTTP/2")
}
if r.Method != "POST" {
return nil, errors.New("invalid gRPC request method")
}
if !strings.Contains(r.Header.Get("Content-Type"), "application/grpc") {
return nil, errors.New("invalid gRPC request content-type")
}
if _, ok := w.(http.Flusher); !ok {
return nil, errors.New("gRPC requires a ResponseWriter supporting http.Flusher")
}
if _, ok := w.(http.CloseNotifier); !ok {
return nil, errors.New("gRPC requires a ResponseWriter supporting http.CloseNotifier")
}
st := &serverHandlerTransport{
rw: w,
req: r,
closedCh: make(chan struct{}),
writes: make(chan func()),
}
if v := r.Header.Get("grpc-timeout"); v != "" {
to, err := timeoutDecode(v)
if err != nil {
return nil, StreamErrorf(codes.Internal, "malformed time-out: %v", err)
}
st.timeoutSet = true
st.timeout = to
}
var metakv []string
for k, vv := range r.Header {
k = strings.ToLower(k)
if isReservedHeader(k) {
continue
}
for _, v := range vv {
if k == "user-agent" {
// user-agent is special. Copying logic of http_util.go.
if i := strings.LastIndex(v, " "); i == -1 {
// There is no application user agent string being set
continue
} else {
v = v[:i]
}
}
metakv = append(metakv, k, v)
}
}
st.headerMD = metadata.Pairs(metakv...)
return st, nil
}
func (s *testServer) EmptyCall(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
if md, ok := metadata.FromContext(ctx); ok {
// For testing purpose, returns an error if there is attached metadata other than
// the user agent set by the client application.
if _, ok := md["user-agent"]; !ok {
return nil, grpc.Errorf(codes.DataLoss, "got extra metadata")
}
var str []string
for _, entry := range md["user-agent"] {
str = append(str, "ua", entry)
}
grpc.SendHeader(ctx, metadata.Pairs(str...))
}
return new(testpb.Empty), nil
}