From 2019e1cb76efa3082159b1add477e7ea8d0896df Mon Sep 17 00:00:00 2001
From: yakud <yakudgm@gmail.com>
Date: Wed, 29 May 2024 17:34:28 +0300
Subject: [PATCH] Add h2c gRPC server wrapper in order to handle HTTP/2
 headers. Add gRPC client playground to debug connection.

---
 cmd/grpc-client-playground/main.go | 55 ++++++++++++++++++++++++++++++
 internal/query/server.go           |  6 ++--
 2 files changed, 59 insertions(+), 2 deletions(-)
 create mode 100644 cmd/grpc-client-playground/main.go

diff --git a/cmd/grpc-client-playground/main.go b/cmd/grpc-client-playground/main.go
new file mode 100644
index 0000000..c671889
--- /dev/null
+++ b/cmd/grpc-client-playground/main.go
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2024 Galactica Network
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+
+	"github.com/Galactica-corp/merkle-proof-service/gen/galactica/merkle"
+)
+
+func main() {
+	// GRPC client for merkle proof service
+	//url := "grpc-merkle-proof-service.galactica.com:443"
+	url := "localhost:50651"
+
+	// Create a new connection
+	conn, err := grpc.Dial(url, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		panic(err)
+	}
+
+	// Close the connection
+	defer conn.Close()
+
+	// Create a new client
+	client := merkle.NewQueryClient(conn)
+	resp, err := client.GetEmptyLeafProof(context.Background(), &merkle.GetEmptyLeafProofRequest{
+		Registry: "0xbc196948e8c1Bc416aEaCf309a63DCEFfdf0cE31",
+	})
+
+	if err != nil {
+		panic(err)
+	}
+
+	// Print the response
+	fmt.Println(resp)
+}
diff --git a/internal/query/server.go b/internal/query/server.go
index 2d99d56..5d1f60c 100644
--- a/internal/query/server.go
+++ b/internal/query/server.go
@@ -27,6 +27,8 @@ import (
 	"github.com/cometbft/cometbft/libs/log"
 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/swaggest/swgui/v5cdn"
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/h2c"
 	"google.golang.org/grpc"
 	"google.golang.org/protobuf/proto"
 
@@ -65,7 +67,6 @@ func NewServer(registryService *zkregistry.Service, logger log.Logger) *Server {
 
 // RunGRPC starts the gRPC server
 func (s *Server) RunGRPC(ctx context.Context, address string) error {
-	// validate address
 	if _, _, err := net.SplitHostPort(address); err != nil {
 		return fmt.Errorf("invalid address: %v", err)
 	}
@@ -91,7 +92,8 @@ func (s *Server) RunGRPC(ctx context.Context, address string) error {
 
 	s.logger.Info("gRPC server started", "address", address)
 
-	if err := grpcServer.Serve(lis); err != nil {
+	handler := h2c.NewHandler(grpcServer, &http2.Server{})
+	if err := http.Serve(lis, handler); err != nil {
 		return fmt.Errorf("failed to serve: %v", err)
 	}