Add request in error handlers

protoc-gen-grpc-gateway/gengateway/template.go

@@ -247,7 +247,7 @@ func Register{{$svc.GetName}}Handler(ctx context.Context, mux *runtime.ServeMux,
 	mux.Handle({{$b.HTTPMethod | printf "%q"}}, pattern_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}}, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
 		resp, err := request_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}}(runtime.AnnotateContext(ctx, req), client, req, pathParams)
 		if err != nil {
-			runtime.HTTPError(ctx, w, err)
+			runtime.HTTPError(ctx, w, req, err)
 			return
 		}
 		{{if $m.GetServerStreaming}}

runtime/errors.go

@@ -58,6 +58,8 @@ var (
 	// HTTPError replies to the request with the error.
 	// You can set a custom function to this variable to customize error format.
 	HTTPError = DefaultHTTPError
+	// This handles the following error used by the gateway: StatusMethodNotAllowed StatusNotFound and StatusBadRequest
+	OtherErrorHandler = DefaultOtherErrorHandler
 )
 
 type errorBody struct {
@@ -70,7 +72,7 @@ type errorBody struct {
 //
 // The response body returned by this function is a JSON object,
 // which contains a member whose key is "error" and whose value is err.Error().
-func DefaultHTTPError(ctx context.Context, w http.ResponseWriter, err error) {
+func DefaultHTTPError(ctx context.Context, w http.ResponseWriter, _ *http.Request, err error) {
 	const fallback = `{"error": "failed to marshal error message"}`
 
 	w.Header().Set("Content-Type", "application/json")
@@ -91,3 +93,7 @@ func DefaultHTTPError(ctx context.Context, w http.ResponseWriter, err error) {
 		glog.Errorf("Failed to write response: %v", err)
 	}
 }
+
+func DefaultOtherErrorHandler(w http.ResponseWriter, _ *http.Request, error string, code int) {
+	http.Error(w, error, code)
+}