Go Kit 사용자 정보 등록/수정/삭제/조회 예제 - DB

SQLite3를 사용하여 사용자 정보를 관리하는 Go Kit 서비스로 변경하려면 SQLite3 데이터베이스를 초기화하고 CRUD 작업을 위한 메서드를 구현해야 합니다. 다음은 SQLite3를 사용하여 사용자 정보를 등록, 수정, 삭제, 조회 및 전체 조회하는 Go Kit API 예제입니다.

프로젝트 구조

프로젝트 구조는 다음과 같습니다:

user-service-db/
├── go.mod
├── go.sum
├── main.go
├── service/
│   ├── models.go
│   └── service.go
├── endpoint/
│   └── endpoint.go
└── transport/
    └── http.go

SQLite3 초기화 및 서비스 구현

먼저, SQLite3 데이터베이스를 초기화하고, 이를 이용해 서비스 메서드를 구현합니다.

main.go

package main

import (
	"log"
	"net/http"
	"user-service-db/endpoint"
	"user-service-db/service"
	"user-service-db/transport"

	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

func main() {
	db, err := gorm.Open(sqlite.Open("users.db"), &gorm.Config{})
	if err != nil {
		log.Fatal(err)
	}

	if err := db.AutoMigrate(&service.User{}); err != nil {
		log.Fatal(err)
	}

	svc := service.NewUserService(db)

	endpoints := endpoint.Endpoints{
		CreateUserEndpoint:  endpoint.MakeCreateUserEndpoint(svc),
		GetUserEndpoint:     endpoint.MakeGetUserEndpoint(svc),
		UpdateUserEndpoint:  endpoint.MakeUpdateUserEndpoint(svc),
		DeleteUserEndpoint:  endpoint.MakeDeleteUserEndpoint(svc),
		GetAllUsersEndpoint: endpoint.MakeGetAllUsersEndpoint(svc),
	}

	r := transport.MakeHTTPHandler(endpoints)

	log.Println("Starting server on :9080...")
	log.Fatal(http.ListenAndServe(":9080", r))
}

service/models.go

사용자 정보를 저장할 데이터 구조체를 정의합니다.

package service

type User struct {
	ID    string `gorm:"primaryKey" json:"id"`
	Name  string `json:"name"`
	Email string `json:"email"`
}

service/service.go

UserService 인터페이스를 구현하는 구조체를 정의합니다.

package service

import (
	"context"

	"gorm.io/gorm"
)

type Service interface {
	CreateUser(ctx context.Context, user User) error
	GetUser(ctx context.Context, id string) (User, error)
	UpdateUser(ctx context.Context, user User) error
	DeleteUser(ctx context.Context, id string) error
	GetAllUsers(ctx context.Context) ([]User, error)
}

type userService struct {
	db *gorm.DB
}

func NewUserService(db *gorm.DB) Service {
	return &userService{db: db}
}

func (s *userService) CreateUser(ctx context.Context, user User) error {
	return s.db.Create(&user).Error
}

func (s *userService) GetUser(ctx context.Context, id string) (User, error) {
	var user User
	if err := s.db.First(&user, "id = ?", id).Error; err != nil {
		return User{}, err
	}
	return user, nil
}

func (s *userService) UpdateUser(ctx context.Context, user User) error {
	return s.db.Save(&user).Error
}

func (s *userService) DeleteUser(ctx context.Context, id string) error {
	return s.db.Delete(&User{}, "id = ?", id).Error
}

func (s *userService) GetAllUsers(ctx context.Context) ([]User, error) {
	var users []User
	if err := s.db.Find(&users).Error; err != nil {
		return nil, err
	}
	return users, nil
}

endpoint/endpoint.go

서비스 메소드를 호출하는 엔드포인트를 정의합니다.

package endpoint

import (
	"context"
	"user-service-db/service"

	"github.com/go-kit/kit/endpoint"
)

type CreateUserRequest struct {
	User service.User
}

type CreateUserResponse struct {
	Err error `json:"error,omitempty"`
}

type GetUserRequest struct {
	ID string `json:"id"`
}

type GetUserResponse struct {
	User service.User `json:"user"`
	Err  error        `json:"err,omitempty"`
}

type UpdateUserRequest struct {
	User service.User `json:"user"`
}

type UpdateUserResponse struct {
	Err error `json:"err,omitempty"`
}

type DeleteUserRequest struct {
	ID string `json:"id"`
}

type DeleteUserResponse struct {
	Err error `json:"err,omitempty"`
}

type GetAllUsersResponse struct {
	Users []service.User `json:"users"`
	Err   error          `json:"err,omitempty"`
}

type Endpoints struct {
	CreateUserEndpoint  endpoint.Endpoint
	GetUserEndpoint     endpoint.Endpoint
	UpdateUserEndpoint  endpoint.Endpoint
	DeleteUserEndpoint  endpoint.Endpoint
	GetAllUsersEndpoint endpoint.Endpoint
}

func MakeCreateUserEndpoint(svc service.Service) endpoint.Endpoint {
	return func(ctx context.Context, request interface{}) (interface{}, error) {
		req := request.(CreateUserRequest)
		err := svc.CreateUser(ctx, service.User{
			ID:    req.User.ID,
			Name:  req.User.Name,
			Email: req.User.Email,
		})
		return CreateUserResponse{Err: err}, err
	}
}

func MakeGetUserEndpoint(svc service.Service) endpoint.Endpoint {
	return func(ctx context.Context, request interface{}) (interface{}, error) {
		req := request.(GetUserRequest)
		user, err := svc.GetUser(ctx, req.ID)
		return GetUserResponse{
			User: service.User{
				ID:    user.ID,
				Name:  user.Name,
				Email: user.Email,
			},
			Err: err,
		}, err
	}
}

func MakeUpdateUserEndpoint(svc service.Service) endpoint.Endpoint {
	return func(ctx context.Context, request interface{}) (interface{}, error) {
		req := request.(UpdateUserRequest)
		err := svc.UpdateUser(ctx, service.User{
			ID:    req.User.ID,
			Name:  req.User.Name,
			Email: req.User.Email,
		})
		return UpdateUserResponse{Err: err}, err
	}
}

func MakeDeleteUserEndpoint(svc service.Service) endpoint.Endpoint {
	return func(ctx context.Context, request interface{}) (interface{}, error) {
		req := request.(DeleteUserRequest)
		err := svc.DeleteUser(ctx, req.ID)
		return DeleteUserResponse{Err: err}, err
	}
}

func MakeGetAllUsersEndpoint(svc service.Service) endpoint.Endpoint {
	return func(ctx context.Context, request interface{}) (interface{}, error) {
		users, err := svc.GetAllUsers(ctx)
		var result []service.User
		for _, u := range users {
			result = append(result, service.User{
				ID:    u.ID,
				Name:  u.Name,
				Email: u.Email,
			})
		}
		return GetAllUsersResponse{Users: result, Err: err}, err
	}
}

transport/http.go

HTTP 핸들러를 정의하고, 엔드포인트와 연결합니다.

package transport

import (
	"context"
	"encoding/json"
	"net/http"
	"user-service-db/endpoint"

	httptransport "github.com/go-kit/kit/transport/http"
	"github.com/gorilla/mux"
)

// Request 디코딩 함수 정의
func decodeCreateUserRequest(_ context.Context, r *http.Request) (interface{}, error) {
	var req endpoint.CreateUserRequest
	if err := json.NewDecoder(r.Body).Decode(&req.User); err != nil {
		return nil, err
	}
	return req, nil
}

func decodeGetUserRequest(_ context.Context, r *http.Request) (interface{}, error) {
	vars := mux.Vars(r)
	return endpoint.GetUserRequest{ID: vars["id"]}, nil
}

func decodeUpdateUserRequest(_ context.Context, r *http.Request) (interface{}, error) {
	var req endpoint.UpdateUserRequest
	if err := json.NewDecoder(r.Body).Decode(&req.User); err != nil {
		return nil, err
	}
	return req, nil
}

func decodeDeleteUserRequest(_ context.Context, r *http.Request) (interface{}, error) {
	vars := mux.Vars(r)
	return endpoint.DeleteUserRequest{ID: vars["id"]}, nil
}

func decodeGetAllUsersRequest(_ context.Context, r *http.Request) (interface{}, error) {
	return nil, nil
}

func encodeResponse(_ context.Context, w http.ResponseWriter, response interface{}) error {
	return json.NewEncoder(w).Encode(response)
}

// HTTP 핸들러 정의
func MakeHTTPHandler(endpoints endpoint.Endpoints) http.Handler {
	r := mux.NewRouter()
	r.Methods("POST").Path("/users").Handler(httptransport.NewServer(
		endpoints.CreateUserEndpoint,
		decodeCreateUserRequest,
		encodeResponse,
	))
	r.Methods("GET").Path("/users/{id}").Handler(httptransport.NewServer(
		endpoints.GetUserEndpoint,
		decodeGetUserRequest,
		encodeResponse,
	))
	r.Methods("PUT").Path("/users").Handler(httptransport.NewServer(
		endpoints.UpdateUserEndpoint,
		decodeUpdateUserRequest,
		encodeResponse,
	))
	r.Methods("DELETE").Path("/users/{id}").Handler(httptransport.NewServer(
		endpoints.DeleteUserEndpoint,
		decodeDeleteUserRequest,
		encodeResponse,
	))
	r.Methods("GET").Path("/users").Handler(httptransport.NewServer(
		endpoints.GetAllUsersEndpoint,
		decodeGetAllUsersRequest,
		encodeResponse,
	))
	return r
}

이 예제는 Go Kit을 사용하여 SQLite3 데이터베이스를 기반으로 사용자 정보를 등록, 조회, 수정, 삭제 및 전체 조회하는 기능을 제공합니다. 이를 통해 보다 영구적인 데이터 저장소를 사용할 수 있습니다.

 

설정 및 실행

% go mod init user-service-db 
go: creating new go.mod: module user-service-db
go: to add module requirements and sums:
        go mod tidy

% go get -u gorm.io/gorm
go: downloading gorm.io/gorm v1.25.11
go: downloading github.com/jinzhu/now v1.1.5
go: downloading github.com/jinzhu/inflection v1.0.0
go: downloading golang.org/x/text v0.14.0
go: added github.com/jinzhu/inflection v1.0.0
go: added github.com/jinzhu/now v1.1.5
go: added golang.org/x/text v0.16.0
go: added gorm.io/gorm v1.25.11

% go get -u gorm.io/driver/sqlite
go: downloading gorm.io/driver/sqlite v1.5.6
go: added github.com/mattn/go-sqlite3 v1.14.22
go: added gorm.io/driver/sqlite v1.5.6

% go mod tidy 
go: finding module for package github.com/gorilla/mux
go: finding module for package github.com/go-kit/kit/log
go: finding module for package github.com/go-kit/kit/endpoint
go: finding module for package github.com/go-kit/kit/transport/http
go: found github.com/go-kit/kit/log in github.com/go-kit/kit v0.13.0
go: found github.com/go-kit/kit/endpoint in github.com/go-kit/kit v0.13.0
go: found github.com/go-kit/kit/transport/http in github.com/go-kit/kit v0.13.0
go: found github.com/gorilla/mux in github.com/gorilla/mux v1.8.1

% go run main.go 
2024/07/18 10:39:23 Starting server on :9080...

테스트 

curl -X POST http://localhost:9080/users -d '{"id":"1","name":"Alice","email":"alice@example.com"}' -H "Content-Type: application/json"
curl -X POST http://localhost:9080/users -d '{"id":"2","name":"KaOk","email":"kaok@example.com"}' -H "Content-Type: application/json"
curl -X GET http://localhost:9080/users -H "Content-Type: application/json"
curl -X GET http://localhost:9080/users/1 -H "Content-Type: application/json"

 

https://github.com/kkaok/study-golang/tree/master/src/user-service-db

study-golang/src/user-service-db at master · kkaok/study-golang

 

출처 : chatGPT