fix(server/v2): post request fallback

server/v2/api/grpcgateway/interceptor.go

@@ -1,6 +1,7 @@
 package grpcgateway
 
 import (
+	"bytes"
 	"errors"
 	"io"
 	"net/http"
@@ -89,7 +90,7 @@ func (g *gatewayInterceptor[T]) ServeHTTP(writer http.ResponseWriter, request *h
 	msgType := gogoproto.MessageType(match.QueryInputName)
 	msg, ok := reflect.New(msgType.Elem()).Interface().(gogoproto.Message)
 	if !ok {
-		runtime.DefaultHTTPProtoErrorHandler(request.Context(), g.gateway, out, writer, request, status.Errorf(codes.Internal, "unable to to create gogoproto message from query input name %s", match.QueryInputName))
+		runtime.HTTPError(request.Context(), g.gateway, out, writer, request, status.Errorf(codes.Internal, "unable to to create gogoproto message from query input name %s", match.QueryInputName))
 		return
 	}
 
@@ -102,12 +103,12 @@ func (g *gatewayInterceptor[T]) ServeHTTP(writer http.ResponseWriter, request *h
 	case http.MethodPost:
 		inputMsg, err = g.createMessageFromPostRequest(in, request, msg)
 	default:
-		runtime.DefaultHTTPProtoErrorHandler(request.Context(), g.gateway, out, writer, request, status.Error(codes.InvalidArgument, "HTTP method was not POST or GET"))
+		runtime.HTTPError(request.Context(), g.gateway, out, writer, request, status.Error(codes.InvalidArgument, "HTTP method was not POST or GET"))
 		return
 	}
 	if err != nil {
 		// the errors returned from the message creation methods return status errors. no need to make one here.
-		runtime.DefaultHTTPProtoErrorHandler(request.Context(), g.gateway, out, writer, request, err)
+		runtime.HTTPError(request.Context(), g.gateway, out, writer, request, err)
 		return
 	}
 
@@ -118,7 +119,7 @@ func (g *gatewayInterceptor[T]) ServeHTTP(writer http.ResponseWriter, request *h
 	if heightStr != "" && heightStr != "latest" {
 		height, err = strconv.ParseUint(heightStr, 10, 64)
 		if err != nil {
-			runtime.DefaultHTTPProtoErrorHandler(request.Context(), g.gateway, out, writer, request, status.Errorf(codes.InvalidArgument, "invalid height in header: %s", heightStr))
+			runtime.HTTPError(request.Context(), g.gateway, out, writer, request, status.Errorf(codes.InvalidArgument, "invalid height in header: %s", heightStr))
 			return
 		}
 	}
@@ -130,7 +131,7 @@ func (g *gatewayInterceptor[T]) ServeHTTP(writer http.ResponseWriter, request *h
 			g.gateway.ServeHTTP(writer, request)
 		} else {
 			// for all other errors, we just return the error.
-			runtime.DefaultHTTPProtoErrorHandler(request.Context(), g.gateway, out, writer, request, err)
+			runtime.HTTPError(request.Context(), g.gateway, out, writer, request, err)
 		}
 		return
 	}
@@ -143,12 +144,17 @@ func (g *gatewayInterceptor[T]) createMessageFromPostRequest(marshaler runtime.M
 	if req.ContentLength > MaxBodySize {
 		return nil, status.Errorf(codes.InvalidArgument, "request body too large: %d bytes, max=%d", req.ContentLength, MaxBodySize)
 	}
-	newReader, err := utilities.IOReaderFactory(req.Body)
+
+	// this block of code ensures that the body can be re-read. this is needed as if the query fails in the
+	// app's query handler, we need to pass the request back to the canonical gateway, which needs to be able to
+	// read the body again.
+	bodyBytes, err := io.ReadAll(req.Body)
 	if err != nil {
 		return nil, status.Errorf(codes.InvalidArgument, "%v", err)
 	}
+	req.Body = io.NopCloser(bytes.NewReader(bodyBytes))
 
-	if err = marshaler.NewDecoder(newReader()).Decode(input); err != nil && !errors.Is(err, io.EOF) {
+	if err = marshaler.NewDecoder(bytes.NewReader(bodyBytes)).Decode(input); err != nil && !errors.Is(err, io.EOF) {
 		return nil, status.Errorf(codes.InvalidArgument, "%v", err)
 	}
 
@@ -217,12 +223,12 @@ func getHTTPGetAnnotationMapping() (map[string]string, error) {
 					continue
 				}
 				queryInputName := string(methodDesc.Input().FullName())
-				annotations := append(httpRule.GetAdditionalBindings(), httpRule)
-				for _, a := range annotations {
-					if httpAnnotation := a.GetGet(); httpAnnotation != "" {
+				httpRules := append(httpRule.GetAdditionalBindings(), httpRule)
+				for _, rule := range httpRules {
+					if httpAnnotation := rule.GetGet(); httpAnnotation != "" {
 						annotationToQueryInputName[httpAnnotation] = queryInputName
 					}
-					if httpAnnotation := a.GetPost(); httpAnnotation != "" {
+					if httpAnnotation := rule.GetPost(); httpAnnotation != "" {
 						annotationToQueryInputName[httpAnnotation] = queryInputName
 					}
 				}

tests/systemtests/distribution_test.go

@@ -179,7 +179,7 @@ func TestDistrValidatorGRPCQueries(t *testing.T) {
 
 	// test validator slashes grpc endpoint
 	slashURL := baseurl + `/cosmos/distribution/v1beta1/validators/%s/slashes`
-	invalidHeightOutput := `{"code":"NUMBER", "details":[]interface {}{}, "message":"strconv.ParseUint: parsing \"NUMBER\": invalid syntax"}`
+	invalidHeightOutput := `{"code":"NUMBER", "details":[], "message":"strconv.ParseUint: parsing \"NUMBER\": invalid syntax"}`
 
 	slashTestCases := []systest.RestTestCase{
 		{