main.go

package main

import (
	"context"
	"crypto/rand"
	"fmt"
	_frontendHttpDelivery "github.com/cooljar/go-postgres-fiber/frontend/delivery/http"
	"github.com/cooljar/go-postgres-fiber/frontend/delivery/http/configs"
	_frontendDeliveryMiddleware "github.com/cooljar/go-postgres-fiber/frontend/delivery/http/middleware"
	_frontendRepo "github.com/cooljar/go-postgres-fiber/frontend/repository/pgsql"
	_frontendUcase "github.com/cooljar/go-postgres-fiber/frontend/usecase"
	"github.com/cooljar/go-postgres-fiber/utils"
	"github.com/gofiber/fiber/v2"
	"github.com/jackc/pgx/v4/pgxpool"
	"io"
	"os"
	"time"

	// docs are generated by Swag CLI, you have to import them.
	_ "github.com/cooljar/go-postgres-fiber/docs" // load API Docs files (Swagger)
)

var dbConn *pgxpool.Pool
var err error

func init() {
	if os.Getenv("SERVER_URL") == "" {
		exitf("SERVER_URL env is required")
	}
	if os.Getenv("SERVER_READ_TIMEOUT") == "" {
		exitf("SERVER_READ_TIMEOUT env is required")
	}
	if os.Getenv("JWT_SECRET_KEY") == "" {
		exitf("JWT_SECRET_KEY env is required")
	}
	if os.Getenv("JWT_SECRET_KEY_EXPIRE_MINUTES") == "" {
		exitf("JWT_SECRET_KEY_EXPIRE_MINUTES env is required")
	}

	if os.Getenv("DB_SERVER_URL") == "" {
		exitf("DB_SERVER_URL env is required")
	}

	if os.Getenv("SMTP_HOST") == "" {
		exitf("SMTP_HOST env is required")
	}
	if os.Getenv("SMTP_PORT") == "" {
		exitf("SMTP_PORT env is required")
	}
	if os.Getenv("SMTP_SENDER_NAME") == "" {
		exitf("SMTP_SENDER_NAME env is required")
	}
	if os.Getenv("SMTP_AUTH_EMAIL") == "" {
		exitf("SMTP_AUTH_EMAIL env is required")
	}
	if os.Getenv("SMTP_AUTH_PASSWORD") == "" {
		exitf("SMTP_AUTH_PASSWORD env is required")
	}

	// Adapted from https://elithrar.github.io/article/generating-secure-random-numbers-crypto-rand/
	assertAvailablePRNG()
}

// assertAvailablePRNG Assert that a cryptographically secure PRNG is available.
// For generation of secure random strings
func assertAvailablePRNG() {
	buf := make([]byte, 1)

	_, err := io.ReadFull(rand.Reader, buf)
	if err != nil {
		exitf("crypto/rand is unavailable: Read() failed with", err)
	}
}

// @title Go Rest API
// @version 1.0
// @description Fiber, PostgreSQL, JWT and Swagger docs in isolated Docker containers.
// @termsOfService http://swagger.io/terms/
// @contact.name API Support
// @contact.email lifelinejar@mail.com
// @license.name Apache 2.0
// @license.url http://www.apache.org/licenses/LICENSE-2.0.html
// @securityDefinitions.apikey ApiKeyAuth
// @in header
// @name Authorization
// @BasePath /api
func main() {
	dbConn, err = pgxpool.Connect(context.Background(), os.Getenv("DB_SERVER_URL"))
	if err != nil {
		exitf("Unable to connect to database: %v\n", err)
	}
	defer dbConn.Close()

	// Define a validator
	validator := utils.NewValidator()

	// Define Fiber config.
	config := configs.FiberConfig()
	app := fiber.New(config)

	// Swagger handler
	_frontendHttpDelivery.NewSwaggerHandler(app)

	middL := _frontendDeliveryMiddleware.InitMiddleware(app)
	app.Use(middL.CORS())
	app.Use(middL.LOGGER())

	// router for public access
	rPublic := app.Group("/api/v1")

	// router for private access
	rPrivate := app.Group("/api/v1/auth", middL.JWT())

	timeoutContext := time.Duration(2) * time.Second

	bookRepo := _frontendRepo.NewPgsqlBookRepository(dbConn)
	bookUsecae := _frontendUcase.NewBookUsecase(bookRepo, timeoutContext)
	_frontendHttpDelivery.NewBookHandler(app, bookUsecae, rPublic, rPrivate)

	userRepo := _frontendRepo.NewPgsqlUserRepository(dbConn)
	userUsecase := _frontendUcase.NewUserUsecase(userRepo, timeoutContext)
	_frontendHttpDelivery.NewUserHandler(app, validator, userUsecase, rPublic, rPrivate)

	utils.StartServer(app)
}

func exitf(s string, args ...interface{}) {
	errorf(s, args...)
	os.Exit(1)
}

func errorf(s string, args ...interface{}) {
	fmt.Fprintf(os.Stderr, s+"\n", args...)
}