Add a config to create new users on startup

internal/createuser/createuser.go

@@ -0,0 +1,82 @@
+package createuser
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"git.artlef.fr/PersonalLibraryManager/internal/config"
+	"git.artlef.fr/PersonalLibraryManager/internal/model"
+	"git.artlef.fr/PersonalLibraryManager/internal/myvalidator"
+	"golang.org/x/crypto/bcrypt"
+	"gorm.io/gorm"
+)
+
+// this method will hash the password
+func CreateUser(db *gorm.DB, username string, password string) error {
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return err
+	}
+	return CreateUserWithHashedPassword(db, username, string(hashedPassword))
+}
+
+// only call this method with hashed password
+func CreateUserWithHashedPassword(db *gorm.DB, username string, hashedPassword string) error {
+	var existingUser model.User
+	err := db.Where("name = ?", username).First(&existingUser).Error
+	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
+		return err
+	}
+	if err == nil {
+		return myvalidator.HttpError{
+			StatusCode: http.StatusInternalServerError,
+			Err:        errors.New("An user with this name already exists."),
+		}
+	}
+	user := model.User{
+		Name:     username,
+		Password: hashedPassword,
+	}
+	return db.Model(&model.User{}).Save(&user).Error
+}
+
+func CreateDefaultUsers(db *gorm.DB, config *config.Config) error {
+	usersPasswordMap := make(map[string]string)
+	var usernames []string
+	for _, s := range config.AddUser {
+		splittedString := strings.Split(s, ":")
+		if len(splittedString) < 2 {
+			return fmt.Errorf("Error when creating user from string %s", s)
+		}
+		usernames = append(usernames, splittedString[0])
+		usersPasswordMap[splittedString[0]] = splittedString[1]
+	}
+
+	var existingUsers []model.User
+	err := db.Where("name IN ?", usernames).Find(&existingUsers).Error
+	if err != nil {
+		return err
+	}
+
+	for _, username := range usernames {
+		if isInExistingUsers(username, existingUsers) {
+			continue
+		}
+		err = CreateUserWithHashedPassword(db, username, usersPasswordMap[username])
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func isInExistingUsers(username string, existingUsers []model.User) bool {
+	for _, existingUser := range existingUsers {
+		if username == existingUser.Name {
+			return true
+		}
+	}
+	return false
+}