[Go] Lambda CRUD với Postgres

Prepare

create simple lambda function, read blog: https://viblo.asia/p/golang-aws-lambda-thong-qua-serverless-framework-phan-1-EoW4ob9xVml
handle request and response in api: https://viblo.asia/p/golang-aws-lambda-thong-qua-serverless-framework-phan-2-5pPLkPY8VRZ

Mục tiêu

add new user
get user by id
update user
delete user

Khởi tạo project

Ở series này mình dùng serverless để làm việc với lambda(env, create, deploy,..)
Để biết chi tiết hơn, checkout link đọc thêm.

Script create table:

sql create table user

CREATETABLE"users"("id" bigserial,
  username charactervarying(50)COLLATE pg_catalog."default",
  name charactervarying(50)COLLATE pg_catalog."default"NOTNULL,
  phone charactervarying(50)COLLATE pg_catalog."default",PRIMARYKEY("id"));

model database

type UserModel struct{
  ID       uint`gorm:"primarykey"`
  UserName string`gorm:"column:username" bson:"username"`
  Email    string`gorm:"column:email" bson:"email"`
  Phone    string`gorm:"column:phone" bson:"phone"`}

List function

file serverless: https://github.com/ducnpdev/open-dev/blob/master/aws/lambda/crud/serverless.yml

Thêm 1 user

tạo endpoint trong file serverless:

functions:create:handler: bin/create # file binary sau khi buildtimeout:3# thời gian tối đa của functoin có thể xử lý memorySize:512# resource memory được cấp phát cho function,description: create new user
    events:-http:path: /create # context-pathmethod: post # method

Code implement:

function connection đến postgres database:

// load env from os, cast to structfuncloadConfig() Postgres {// những value khi get từ os lên thì đã được define trong file serverless.yaml
    user := os.Getenv("DB_USER")
    dbpass := os.Getenv("DB_PASS")
    dbhost := os.Getenv("DB_HOST")
    dbservice := os.Getenv("DB_SERVICE")return Postgres{
      Username: user,
      Password: dbpass,
      Database: dbservice,
      Host:     dbhost,
      Port:5432,}}// create database postgres instancefuncInitPostgres()(*gorm.DB,error){
    log.Default().Println("connecting postgres database")
    config :=loadConfig()
    dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%d ", config.Host, config.Username, config.Password, config.Database, config.Port)
    db, err := gorm.Open(postgres.Open(dsn),&gorm.Config{})if err !=nil{
        log.Default().Println("connect postgres err:", err)return db, err
    }
    log.Default().Println("connect postgres successfully")return db, err
}

struct nhận request client:

type UserDTO struct{
  Email string`json:"email"`
  User  string`json:"userName"`
  Phone string`json:"phone"`}

main function của lambda

funcmain(){
    lambda.Start(CreateUser)}

function response data

funcParseResponse(respBody HttpResponse)string{
  respBody.Time = time.Now().Format("2006-01-02T15:04:05.000-07:00")if respBody.Err !=nil{returnresponseErr(respBody)}returnresponseOk(respBody)}funcresponseOk(respBody HttpResponse)string{var buf bytes.Buffer
  mapRes :=map[string]interface{}{"responseId":      respBody.Uuid,"responseMessage":"successfully","responseTime":    respBody.Time,}if respBody.Data !=nil{
    mapRes["data"]= respBody.Data
  }
  body, errMarshal := json.Marshal(mapRes)if errMarshal !=nil{
    log.Default().Println("marshal response err", errMarshal)}
  json.HTMLEscape(&buf, body)return buf.String()}funcresponseErr(respBody HttpResponse)string{var buf bytes.Buffer
  mapRes :=map[string]interface{}{"responseId":      respBody.Uuid,"responseMessage": respBody.Err.Error(),"responseTime":    respBody.Time,}

  body, errMarshal := json.Marshal(mapRes)if errMarshal !=nil{
    log.Default().Println("marshal response err", errMarshal)}
  json.HTMLEscape(&buf, body)return buf.String()}

function createUser

funcCreateUser(ctx context.Context,
  eventReq events.APIGatewayProxyRequest)(Response,error){var(
    req  = RequestBodyAPIGW{}
    resp = Response{
      StatusCode:400,
      IsBase64Encoded:false,
      Headers:map[string]string{"Content-Type":"application/json",},})
  err := json.Unmarshal([]byte(eventReq.Body),&req)if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})return resp,nil}
  db, err := pkg.InitPostgres()if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})
    resp.StatusCode =500return resp,nil}// set http-code 200
  resp.StatusCode =200// save new user
  err = db.Debug().Exec(`insert into users(username,email,phone) values(?,?,?)`, req.Data.User, req.Data.Email, req.Data.Phone).Error
  if err !=nil{
    resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Err: err})return resp,nil}
  resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Data:nil})return resp,nil}

Get user by id

tạo endpoint trong file serverless:

functions:read:handler: bin/read
    description: get user detail by id
    events:-http:path: /read
          method: get

Code implement:

Struct nhận request từ client

type UserDTO struct{
  ID string`json:"userId"`}

function get user detail by id

funcReadUser(ctx context.Context,
  eventReq events.APIGatewayProxyRequest)(Response,error){var(
    req  = RequestBodyAPIGW{}
    resp = Response{
      StatusCode:400,
      IsBase64Encoded:false,
      Headers:map[string]string{"Content-Type":"application/json",},})// get parameter from url
  req.Data.ID = eventReq.QueryStringParameters["id"]// init database,
  db, err := pkg.InitPostgres()if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})
    resp.StatusCode =500return resp,nil}
  resp.StatusCode =200var user = models.UserModel{}
  err = db.Table("users").Where("id = ?", req.Data.ID).First(&user).Error
  if err !=nil{
    resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Err: err})return resp,nil}
  resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Data: user})return resp,nil}

Get update user

tạo endpoint trong file serverless

functions:
  update:
    handler: bin/update
    description: update user by id
    events:
      - http:
          path: /update
          method: post

Struct nhận request từ client

type UserDTO struct{
    ID    int`json:"userId"`
    Email string`json:"email"`
    Phone string`json:"phone"`}

Code implement

function get update user

funcUpdateUser(ctx context.Context, eventReq events. APIGatewayProxyRequest)(Response,error){var(
    req  = RequestBodyAPIGW{}
    resp = Response{
      StatusCode:400,
      IsBase64Encoded:false,
      Headers:map[string]string{"Content-Type":"application/json",},})
  err := json.Unmarshal([]byte(eventReq.Body),&req)if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})return resp,nil}
  db, err := pkg.InitPostgres()if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})
    resp.StatusCode =500return resp,nil}
  resp.StatusCode =200
  err = db.Exec(`update users set email = ?, phone = ? where id = ?`, req.Data.Email, req.Data.Phone, req.Data.ID).Error
  if err !=nil{
    resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Err: err})return resp,nil}
  resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Data:nil})return resp,nil}

Detele user

tạo endpoint trong file serverless

functions:
  delete:
    handler: bin/delete
    description: delete user by id
    events:
      - http:
          path: /delete
          method: post

Struct nhận request từ client

type UserDTO struct{
    ID    int`json:"userId"`}

Code implement

function get delete user by id

funcDeleteUser(ctx context.Context, eventReq events.APIGatewayProxyRequest)(Response,error){var(
    req  = RequestBodyAPIGW{}
    resp = Response{
      StatusCode:400,
      IsBase64Encoded:false,
      Headers:map[string]string{"Content-Type":"application/json",},})
  err := json.Unmarshal([]byte(eventReq.Body),&req)if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})return resp,nil}
  db, err := pkg.InitPostgres()if err !=nil{
    resp.Body =ParseResponse(HttpResponse{
      Uuid: req.RequestID,
      Err:  err,})
    resp.StatusCode =500return resp,nil}
  resp.StatusCode =200var user = models.UserModel{}
  err = db.Debug().Table("users").Delete(&user, req.Data.ID).Error
  if err !=nil{
    resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Err: err})return resp,nil}
  resp.Body =ParseResponse(HttpResponse{Uuid: req.RequestID, Data: req.Data})return resp,nil}

Nguồn: viblo.asia

Prepare

Mục tiêu

Khởi tạo project

Script create table:

List function

Thêm 1 user

Get user by id

Get update user

Detele user

Bài viết liên quan

WebP là gì? Hướng dẫn cách để chuyển hình ảnh jpg, png qua webp

Điểm khác biệt giữa IPv4 và IPv6 là gì?

Check nameservers của tên miền xem website trỏ đúng chưa

Mình đang dùng Google Domains để check tên miền hàng ngày

Liên hệ

THÔNG TIN

Địa chỉ