[hw-8] add: comment service

comments/internal/app/app.go

@@ -0,0 +1,190 @@
+package app
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"os"
+	"route256/comments/infra/config"
+	"route256/comments/infra/db/postgres"
+	"route256/comments/internal/app/server"
+	"route256/comments/internal/domain/service"
+	"time"
+
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/reflection"
+
+	mw "route256/comments/infra/grpc/middleware"
+	repository "route256/comments/infra/repository/sqlc"
+
+	pb "route256/pkg/api/comments/v1"
+)
+
+type App struct {
+	config     *config.Config
+	controller *server.Server
+
+	grpcServer *grpc.Server
+	httpServer *http.Server
+	gwConn     *grpc.ClientConn
+}
+
+func NewApp(configPath string) (*App, error) {
+	c, err := config.LoadConfig(configPath)
+	if err != nil {
+		return nil, fmt.Errorf("unable to load config: %w", err)
+	}
+
+	log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr})
+	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+
+	if c.Service.LogLevel != "" {
+		level, logErr := zerolog.ParseLevel(c.Service.LogLevel)
+		if logErr != nil {
+			return nil, fmt.Errorf("unknown log level `%s` provided: %w", c.Service.LogLevel, logErr)
+		}
+
+		zerolog.SetGlobalLevel(level)
+	}
+
+	log.WithLevel(zerolog.GlobalLevel()).Msgf("using logging level=`%s`", zerolog.GlobalLevel().String())
+
+	shards, err := getPostgresPools(c)
+	if err != nil {
+		return nil, err
+	}
+
+	repo := repository.NewCommentsRepository(shards[0], shards[1])
+
+	service := service.NewCommentsService(repo, c.App.EditInterval)
+	controller := server.NewServer(service)
+
+	app := &App{
+		config:     c,
+		controller: controller,
+	}
+
+	return app, nil
+}
+
+func (app *App) Shutdown(ctx context.Context) (err error) {
+	if app.httpServer != nil {
+		err = app.httpServer.Shutdown(ctx)
+		if err != nil {
+			log.Error().Err(err).Msgf("failed http gateway server shutdown")
+		}
+	}
+
+	done := make(chan struct{})
+	if app.grpcServer != nil {
+		go func() {
+			app.grpcServer.GracefulStop()
+
+			close(done)
+		}()
+	}
+
+	select {
+	case <-done:
+	case <-ctx.Done():
+		if app.grpcServer != nil {
+			app.grpcServer.Stop()
+		}
+	}
+
+	if app.gwConn != nil {
+		err2 := app.gwConn.Close()
+
+		if err2 != nil {
+			err = err2
+
+			log.Error().Err(err).Msgf("failed gateway connection close")
+		}
+	}
+
+	return err
+}
+
+func (app *App) ListenAndServe(ctx context.Context) error {
+	grpcAddr := fmt.Sprintf("%s:%s", app.config.Service.Host, app.config.Service.GRPCPort)
+	l, err := net.Listen("tcp", grpcAddr)
+	if err != nil {
+		return err
+	}
+
+	app.grpcServer = grpc.NewServer(
+		grpc.ChainUnaryInterceptor(
+			mw.Logging,
+			mw.Validate,
+		),
+	)
+	reflection.Register(app.grpcServer)
+
+	pb.RegisterCommentsServer(app.grpcServer, app.controller)
+
+	go func() {
+		if err = app.grpcServer.Serve(l); err != nil {
+			log.Fatal().Err(err).Msg("failed to serve")
+		}
+	}()
+
+	log.Info().Msgf("Serving grpc loms at grpc://%s", l.Addr())
+
+	// Setup HTTP gateway
+
+	conn, err := grpc.NewClient(
+		grpcAddr,
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+	)
+	if err != nil {
+		return fmt.Errorf("grpc.NewClient: %w", err)
+	}
+	app.gwConn = conn
+
+	gwmux := runtime.NewServeMux()
+	if err = pb.RegisterCommentsHandler(ctx, gwmux, conn); err != nil {
+		return fmt.Errorf("pb.RegisterLOMSHandler: %w", err)
+	}
+
+	root := http.NewServeMux()
+	root.Handle("/metrics", promhttp.Handler())
+	root.Handle("/", gwmux)
+
+	app.httpServer = &http.Server{
+		Addr:        fmt.Sprintf("%s:%s", app.config.Service.Host, app.config.Service.HTTPPort),
+		Handler:     root,
+		ReadTimeout: 10 * time.Second,
+	}
+
+	log.Info().Msgf("Serving http loms at http://%s", app.httpServer.Addr)
+
+	return app.httpServer.ListenAndServe()
+}
+
+func getPostgresPools(c *config.Config) ([]*pgxpool.Pool, error) {
+	conns := make([]string, len(c.DbShards))
+	for i, shard := range c.DbShards {
+		conns[i] = fmt.Sprintf(
+			"postgresql://%s:%s@%s:%s/%s?sslmode=disable",
+			shard.User,
+			shard.Password,
+			shard.Host,
+			shard.Port,
+			shard.DBName,
+		)
+	}
+
+	pools, err := postgres.NewPools(context.Background(), conns...)
+	if err != nil {
+		return nil, err
+	}
+
+	return pools, nil
+}