feature/train-go-lesson-3 (#8)

Reviewed-on: https://git.gocommunity.ru/walleri1/go_winter_work_2025/pulls/8
Co-authored-by: Vitaliy Turov <walleri1@yandex.ru>
Co-committed-by: Vitaliy Turov <walleri1@yandex.ru>

go/lesson3/.gitignore

@@ -0,0 +1,15 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/

go/lesson3/controllers/controllers.go

@@ -0,0 +1,134 @@
+package controllers
+
+import (
+	strconv "strconv"
+	time "time"
+
+	fiber "github.com/gofiber/fiber/v2"
+	jwt "github.com/golang-jwt/jwt"
+	bcrypt "golang.org/x/crypto/bcrypt"
+	database "lesson3/database"
+	models "lesson3/models"
+)
+
+func Register(c *fiber.Ctx) error {
+	var data map[string]string
+
+	if err := c.BodyParser(&data); err != nil {
+		return err
+	}
+
+	password, _ := bcrypt.GenerateFromPassword(
+		[]byte(data["password"]),
+		14,
+	) // GenerateFromPassword returns the bcrypt hash of the password at the given cost i.e. (14 in our case).
+
+	user := models.User{
+		Name:     data["name"],
+		Email:    data["email"],
+		Password: password,
+	}
+
+	database.DB.Create(&user) // Adds the data to the DB
+
+	return c.JSON(user)
+}
+
+const SecretKey = "secret"
+
+func Login(c *fiber.Ctx) error {
+	var data map[string]string
+
+	if err := c.BodyParser(&data); err != nil {
+		return err
+	}
+
+	var user models.User
+
+	database.DB.Where("email = ?", data["email"]).
+		First(&user)
+		// Check the email is present in the DB
+
+	if user.ID == 0 { // If the ID return is '0' then there is no such email present in the DB
+		c.Status(fiber.StatusNotFound)
+		return c.JSON(fiber.Map{
+			"message": "user not found",
+		})
+	}
+
+	if err := bcrypt.CompareHashAndPassword(user.Password, []byte(data["password"])); err != nil {
+		c.Status(fiber.StatusBadRequest)
+		return c.JSON(fiber.Map{
+			"message": "incorrect password",
+		})
+	} // If the email is present in the DB then compare the Passwords and if incorrect password then return error.
+
+	claims := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.StandardClaims{
+		Issuer:    strconv.Itoa(int(user.ID)),
+		ExpiresAt: time.Now().Add(time.Hour * 24).Unix(), // 1 day
+	})
+
+	token, err := claims.SignedString([]byte(SecretKey))
+	if err != nil {
+		c.Status(fiber.StatusInternalServerError)
+		return c.JSON(fiber.Map{
+			"message": "could not login",
+		})
+	}
+
+	cookie := fiber.Cookie{
+		Name:     "jwt",
+		Value:    token,
+		Expires:  time.Now().Add(time.Hour * 24),
+		HTTPOnly: true,
+	}
+
+	c.Cookie(&cookie)
+
+	return c.JSON(fiber.Map{
+		"message": "success",
+	})
+}
+
+func User(c *fiber.Ctx) error {
+	cookie := c.Cookies("jwt")
+
+	token, err := jwt.ParseWithClaims(
+		cookie,
+		&jwt.StandardClaims{},
+		func(token *jwt.Token) (interface{}, error) {
+			return []byte(SecretKey), nil
+		},
+	)
+	if err != nil {
+		c.Status(fiber.StatusUnauthorized)
+		return c.JSON(fiber.Map{
+			"message": "unauthenticated",
+		})
+	}
+
+	claims := token.Claims.(*jwt.StandardClaims)
+
+	var user models.User
+
+	database.DB.Where("id = ?", claims.Issuer).First(&user)
+
+	return c.JSON(user)
+}
+
+func Logout(c *fiber.Ctx) error {
+	cookie := fiber.Cookie{
+		Name:  "jwt",
+		Value: "",
+		Expires: time.Now().
+			Add(-time.Hour),
+		// Sets the expiry time an hour ago in the past.
+		HTTPOnly: true,
+	}
+
+	c.Cookie(&cookie)
+
+	return c.JSON(fiber.Map{
+		"message": "success",
+	})
+}

go/lesson3/database/dbconn.go

@@ -0,0 +1,37 @@
+package database
+
+import (
+	fmt "fmt"
+	log "log"
+
+	postgres "gorm.io/driver/postgres"
+	gorm "gorm.io/gorm"
+
+	models "lesson3/models"
+)
+
+const (
+	host     = "localhost"
+	port     = 5432
+	user     = "postgres"
+	password = "password"
+	dbname   = "lesson3"
+)
+
+var dsn string = fmt.Sprintf("host=%s port=%d user=%s "+
+	"password=%s dbname=%s sslmode=disable TimeZone=Asia/Shanghai",
+	host, port, user, password, dbname)
+
+var DB *gorm.DB
+
+func DBconn() {
+	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
+	if err != nil {
+		log.Fatal(err)
+	}
+	DB = db
+
+	db.AutoMigrate(
+		&models.User{},
+	) // we are going to create a models.go file for the User Model.
+}

go/lesson3/go.mod

@@ -0,0 +1,35 @@
+module lesson3
+
+go 1.19
+
+require (
+	github.com/gofiber/fiber/v2 v2.40.1
+	github.com/golang-jwt/jwt v3.2.2+incompatible
+)
+
+require (
+	github.com/andybalholm/brotli v1.0.4 // indirect
+	github.com/jackc/chunkreader/v2 v2.0.1 // indirect
+	github.com/jackc/pgconn v1.13.0 // indirect
+	github.com/jackc/pgio v1.0.0 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgproto3/v2 v2.3.1 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b // indirect
+	github.com/jackc/pgtype v1.12.0 // indirect
+	github.com/jackc/pgx/v4 v4.17.2 // indirect
+	github.com/jinzhu/inflection v1.0.0 // indirect
+	github.com/jinzhu/now v1.1.4 // indirect
+	github.com/klauspost/compress v1.15.9 // indirect
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.16 // indirect
+	github.com/mattn/go-runewidth v0.0.14 // indirect
+	github.com/rivo/uniseg v0.2.0 // indirect
+	github.com/valyala/bytebufferpool v1.0.0 // indirect
+	github.com/valyala/fasthttp v1.41.0 // indirect
+	github.com/valyala/tcplisten v1.0.0 // indirect
+	golang.org/x/crypto v0.0.0-20220722155217-630584e8d5aa
+	golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab // indirect
+	golang.org/x/text v0.3.7 // indirect
+	gorm.io/driver/postgres v1.4.5
+	gorm.io/gorm v1.24.1-0.20221019064659-5dd2bb482755
+)

go/lesson3/main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	fiber "github.com/gofiber/fiber/v2"
+	cors "github.com/gofiber/fiber/v2/middleware/cors"
+
+	database "lesson3/database"
+	routes "lesson3/routes"
+)
+
+func main() {
+	database.DBconn()
+
+	app := fiber.New()
+
+	app.Use(cors.New(cors.Config{
+		AllowCredentials: true,
+	}))
+
+	routes.Setup(app)
+
+	app.Listen(":8000")
+}

go/lesson3/models/models.go

@@ -0,0 +1,12 @@
+package models
+
+import (
+	gorm "gorm.io/gorm"
+)
+
+type User struct {
+	gorm.Model
+	Name     string `json:"name"`
+	Email    string `json:"email" gorm:"unique"`
+	Password []byte `json:"-"`
+}

go/lesson3/routes/routes.go

@@ -0,0 +1,19 @@
+package routes
+
+import (
+	controllers "lesson3/controllers"
+
+	fiber "github.com/gofiber/fiber/v2"
+)
+
+func Setup(app *fiber.App) {
+	api := app.Group("/user")
+
+	api.Get("/get-user", controllers.User)
+
+	api.Post("/register", controllers.Register)
+
+	api.Post("/login", controllers.Login)
+
+	api.Post("/logout", controllers.Logout)
+}