Files
3ybactuk-marketplace-go-ser…/cart/internal/app/app.go
Никита Шубин 4396bebe80 [hw-7] add metrics, tracing
2025-07-26 14:15:40 +00:00

146 lines
3.9 KiB
Go

package app
import (
"context"
"fmt"
"net"
"net/http"
"os"
"time"
"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"
"route256/cart/internal/app/server"
loms_service "route256/cart/internal/clients/loms"
product_service "route256/cart/internal/clients/products"
"route256/cart/internal/domain/repository"
"route256/cart/internal/domain/service"
"route256/cart/internal/infra/config"
"route256/cart/internal/infra/http/middlewares"
"route256/cart/internal/infra/http/round_trippers"
pbLOMS "route256/pkg/api/loms/v1"
)
const (
productsRetryAttemptsDefault = 3
productsInitialDelaySecDefault = 1
)
type App struct {
config *config.Config
server http.Server
}
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())
app := &App{
config: c,
}
service, err := app.setupCartService()
if err != nil {
return nil, err
}
app.server.Handler = app.BootstrapHandlers(service)
return app, nil
}
func (app *App) Shutdown(ctx context.Context) error {
return app.server.Shutdown(ctx)
}
func (app *App) ListenAndServe(_ context.Context) error {
address := fmt.Sprintf("%s:%s", app.config.Service.Host, app.config.Service.Port)
l, err := net.Listen("tcp", address)
if err != nil {
return err
}
log.Info().Msgf("Serving cart at http://%s", l.Addr())
return app.server.Serve(l)
}
func (app *App) setupCartService() (*service.CartService, error) {
// Product service client
transport := http.DefaultTransport
transport = round_trippers.NewLogRoundTripper(transport)
transport = round_trippers.NewMetricsRoundTripper(transport)
transport = round_trippers.NewRetryRoundTripper(transport, productsRetryAttemptsDefault, productsInitialDelaySecDefault)
httpClient := http.Client{
Transport: transport,
Timeout: 10 * time.Second,
}
productService := product_service.NewProductService(
httpClient,
app.config.ProductService.Token,
fmt.Sprintf("%s:%s", app.config.ProductService.Host, app.config.ProductService.Port),
app.config.ProductService.Limit,
app.config.ProductService.Burst,
app.config.Service.Workers,
)
// LOMS service client
conn, err := grpc.NewClient(
fmt.Sprintf("%s:%s", app.config.LomsService.Host, app.config.LomsService.Port),
grpc.WithTransportCredentials(insecure.NewCredentials()))
if err != nil {
return nil, fmt.Errorf("grpc.NewClient: %w", err)
}
lomsClient := pbLOMS.NewLOMSClient(conn)
lomsService := loms_service.NewLomsService(lomsClient)
const userCartCap = 100
cartRepository := repository.NewInMemoryRepository(userCartCap)
return service.NewCartService(cartRepository, productService, lomsService), nil
}
func (app *App) BootstrapHandlers(cartService *service.CartService) http.Handler {
s := server.NewServer(cartService)
mx := http.NewServeMux()
mx.HandleFunc("POST /user/{user_id}/cart/{sku_id}", s.AddItemHandler)
mx.HandleFunc("POST /checkout/{user_id}", s.CheckoutHandler)
mx.HandleFunc("GET /user/{user_id}/cart", s.GetItemsByUserIDHandler)
mx.HandleFunc("DELETE /user/{user_id}/cart/{sku_id}", s.DeleteItemHandler)
mx.HandleFunc("DELETE /user/{user_id}/cart", s.DeleteItemsByUserIDHandler)
mx.Handle("GET /metrics", promhttp.Handler())
h := middlewares.NewTracingMiddleware(mx)
h = middlewares.NewMetricsMiddleware(h)
h = middlewares.NewTimerMiddleware(h)
return h
}