feat: added http gateway for grpc

internal/config/config.go

@@ -11,38 +11,44 @@ import (
 type Config struct {
 	GRPCPort             int
 	GRPCEnableReflection bool
+	EnableHTTPHandler    bool
+	HTTPPort             int
 	LogLevel             string
 }
 
 func Load() (*Config, error) {
-	if err := godotenv.Load(); err != nil {
-		log.Printf("Warning: .env file not found: %v", err)
-	}
+	_ = godotenv.Load()
 
-	config := &Config{}
-
-	portStr := getEnv("GRPC_PORT", "50051")
-	port, err := strconv.Atoi(portStr)
-	if err != nil {
-		return nil, err
-	}
-	config.GRPCPort = port
-
-	enableReflectionStr := getEnv("GRPC_ENABLE_REFLECTION", "false")
-	enableReflection, err := strconv.ParseBool(enableReflectionStr)
-	if err != nil {
-		return nil, err
-	}
-	config.GRPCEnableReflection = enableReflection
-
-	config.LogLevel = getEnv("LOG_LEVEL", "info")
-
-	return config, nil
+	return &Config{
+		GRPCPort:             mustGetInt("GRPC_PORT", 50051), //nolint:mnd // false-positive
+		GRPCEnableReflection: mustGetBool("GRPC_ENABLE_REFLECTION", false),
+		EnableHTTPHandler:    mustGetBool("HTTP_HANDLER_ENABLE", false),
+		HTTPPort:             mustGetInt("HTTP_PORT", 8080), //nolint:mnd // false-positive
+		LogLevel:             getEnv("LOG_LEVEL", "info"),
+	}, nil
 }
 
-func getEnv(key, defaultValue string) string {
-	if value := os.Getenv(key); value != "" {
-		return value
+func getEnv(key, def string) string {
+	if val := os.Getenv(key); val != "" {
+		return val
 	}
-	return defaultValue
+	return def
+}
+
+func mustGetInt(key string, def int) int {
+	val := getEnv(key, strconv.Itoa(def))
+	n, err := strconv.Atoi(val)
+	if err != nil {
+		log.Fatalf("invalid int for %s: %v", key, err)
+	}
+	return n
+}
+
+func mustGetBool(key string, def bool) bool {
+	val := getEnv(key, strconv.FormatBool(def))
+	b, err := strconv.ParseBool(val)
+	if err != nil {
+		log.Fatalf("invalid bool for %s: %v", key, err)
+	}
+	return b
 }

internal/server/server.go

@@ -1,9 +1,11 @@
 package server
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"net"
+	"net/http"
 
 	"orderservice/internal/config"
 	"orderservice/internal/interceptor"
@@ -14,7 +16,9 @@ import (
 
 	pb "orderservice/pkg/api/order"
 
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/reflection"
 )
 
@@ -37,6 +41,22 @@ func New(cfg *config.Config) *Server {
 	}
 }
 
+func runHTTPHandler(s *Server, grpcServerEndpoint *string) error {
+	ctx := context.Background()
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	mux := runtime.NewServeMux()
+	opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
+	err := pb.RegisterOrderServiceHandlerFromEndpoint(ctx, mux, *grpcServerEndpoint, opts)
+	if err != nil {
+		return err
+	}
+
+	addr := fmt.Sprintf(":%d", s.config.HTTPPort)
+	return http.ListenAndServe(addr, mux)
+}
+
 func (s *Server) RegisterServices() {
 	repo := orderInMemory.NewOrderRepository()
 	orderService := service.NewOrderService(repo)
@@ -57,6 +77,15 @@ func (s *Server) Start() error {
 		return fmt.Errorf("failed to listen: %w", err)
 	}
 
+	if s.config.EnableHTTPHandler {
+		go func() {
+			log.Printf("Starting HTTP gateway on port %d", s.config.HTTPPort)
+			if err := runHTTPHandler(s, &addr); err != nil {
+				log.Printf("HTTP gateway failed: %v", err)
+			}
+		}()
+	}
+
 	log.Printf("Starting gRPC server on port %d", s.config.GRPCPort)
 
 	if err := s.grpcServer.Serve(lis); err != nil {