快速搭建一個go語言web後端服務腳手架
原始碼：https://github.com/weloe/go-web-demo
web框架使用gin，資料操作使用gorm，存取控制使用casbin
首先新增一下自定義的middleware
recover_control.go ，統一處理panic error返回的資訊
package middleware
import (
"fmt"
"github.com/gin-gonic/gin"
"go-web-demo/component"
"log"
"net/http"
)
func Recover(c *gin.Context) {
defer func() {
if r := recover(); r != nil {
// print err msg
log.Printf("panic: %v\n", r)
// debug.PrintStack()
// response same struct
c.JSON(http.StatusBadRequest, component.RestResponse{Code: -1, Message: fmt.Sprintf("%v", r)})
}
}()
c.Next()
}
access_control.go 使用casbin進行存取控制的中介軟體
package middleware
import (
"fmt"
"github.com/casbin/casbin/v2"
gormadapter "github.com/casbin/gorm-adapter/v3"
"github.com/gin-gonic/gin"
_ "github.com/go-sql-driver/mysql"
"go-web-demo/component"
"log"
"net/http"
)
// DefaultAuthorize determines if current subject has been authorized to take an action on an object.
func DefaultAuthorize(obj string, act string) gin.HandlerFunc {
return func(c *gin.Context) {
// Get current user/subject
token := c.Request.Header.Get("token")
if token == "" {
c.AbortWithStatusJSON(http.StatusUnauthorized, component.RestResponse{Message: "token is nil"})
return
}
username, err := component.GlobalCache.Get(token)
if err != nil || string(username) == "" {
log.Println(err)
c.AbortWithStatusJSON(http.StatusUnauthorized, component.RestResponse{Message: "user hasn't logged in yet"})
return
}
// Casbin enforces policy
ok, err := enforce(string(username), obj, act, component.Enforcer)
if err != nil {
log.Println(err)
c.AbortWithStatusJSON(http.StatusInternalServerError, component.RestResponse{Message: "error occurred when authorizing user"})
return
}
if !ok {
c.AbortWithStatusJSON(http.StatusForbidden, component.RestResponse{Message: "forbidden"})
return
}
c.Next()
}
}
func enforce(sub string, obj string, act string, enforcer *casbin.Enforcer) (bool, error) {
// Load policies from DB dynamically
err := enforcer.LoadPolicy()
if err != nil {
return false, fmt.Errorf("failed to load policy from DB: %w", err)
}
// Verify
ok, err := enforcer.Enforce(sub, obj, act)
return ok, err
}
func AuthorizeAdapterAndModel(obj string, act string, adapter *gormadapter.Adapter, model string) gin.HandlerFunc {
return func(c *gin.Context) {
// Get current user/subject
token := c.Request.Header.Get("token")
if token == "" {
c.AbortWithStatusJSON(401, component.RestResponse{Message: "token is nil"})
return
}
username, err := component.GlobalCache.Get(token)
if err != nil || string(username) == "" {
log.Println(err)
c.AbortWithStatusJSON(401, component.RestResponse{Message: "user hasn't logged in yet"})
return
}
// Load model configuration file and policy store adapter
enforcer, err := casbin.NewEnforcer(model, adapter)
// Casbin enforces policy
ok, err := enforce(string(username), obj, act, enforcer)
if err != nil {
log.Println(err)
c.AbortWithStatusJSON(500, component.RestResponse{Message: "error occurred when authorizing user"})
return
}
if !ok {
c.AbortWithStatusJSON(403, component.RestResponse{Message: "forbidden"})
return
}
c.Next()
}
}
reader.go 讀取yaml組態檔的根據類，使用了viter
package config
import (
"fmt"
"github.com/spf13/viper"
"log"
"sync"
"time"
)
type Config struct {
Server *Server
Mysql *DB
LocalCache *LocalCache
Casbin *Casbin
}
type Server struct {
Port int64
}
type DB struct {
Username string
Password string
Host string
Port int64
Dbname string
TimeOut string
}
type LocalCache struct {
ExpireTime time.Duration
}
type Casbin struct {
Model string
}
var (
once sync.Once
Reader = new(Config)
)
func (config *Config) ReadConfig() *Config {
once.Do(func() {
viper.SetConfigName("config") // filename
viper.SetConfigType("yaml") // filename extension : yaml | json |
viper.AddConfigPath("./config") // workspace dir : ./
var err error
err = viper.ReadInConfig() // read config
if err != nil { // handler err
log.Fatalf(fmt.Sprintf("Fatal error config file: %s \n", err))
}
err = viper.Unmarshal(config)
if err != nil {
log.Fatalf(fmt.Sprintf("Fatal error viper unmarshal config: %s \n", err))
}
})
return Reader
}
組態檔
server:
port: 8080
mysql:
username: root
password: pwd
host: 127.0.0.1
port: 3306
dbname: casbin_demo
timeout: 10s
localCache:
expireTime: 60
casbin:
model: config/rbac_model.conf
persistence.go， gorm，bigcache, casbin 初始化，這裡用的casbin是從資料庫讀取policy
package component
import (
"fmt"
"github.com/allegro/bigcache"
"github.com/casbin/casbin/v2"
gormadapter "github.com/casbin/gorm-adapter/v3"
_ "github.com/go-sql-driver/mysql"
"go-web-demo/config"
"gorm.io/driver/mysql"
"gorm.io/gorm"
"log"
"time"
)
var (
DB *gorm.DB
GlobalCache *bigcache.BigCache
Enforcer *casbin.Enforcer
)
// CreateByConfig create components
func CreateByConfig() {
ConnectDB()
CreateLocalCache()
CreateCasbinEnforcer()
}
func ConnectDB() {
// connect to DB
var err error
dbConfig := config.Reader.ReadConfig().Mysql
if dbConfig == nil {
log.Fatalf(fmt.Sprintf("db config is nil"))
}
// config
username := dbConfig.Username
password := dbConfig.Password
host := dbConfig.Host
port := dbConfig.Port
Dbname := dbConfig.Dbname
timeout := dbConfig.TimeOut
dbUrl := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8&parseTime=True&loc=Local&timeout=%s", username, password, host, port, Dbname, timeout)
log.Println("connect db url: " + dbUrl)
DB, err = gorm.Open(mysql.Open(dbUrl), &gorm.Config{})
if err != nil {
log.Fatalf(fmt.Sprintf("failed to connect to DB: %v", err))
}
}
func CreateLocalCache() {
var err error
cacheConfig := config.Reader.ReadConfig().LocalCache
if cacheConfig == nil {
log.Fatalf(fmt.Sprintf("cache config is nil"))
}
// Initialize cache to store current user in cache.
GlobalCache, err = bigcache.NewBigCache(bigcache.DefaultConfig(cacheConfig.ExpireTime * time.Second)) // Set expire time to 30 s
if err != nil {
log.Fatalf(fmt.Sprintf("failed to initialize cahce: %v", err))
}
}
func CreateCasbinEnforcer() {
var err error
// casbin model
config := config.Reader.ReadConfig().Casbin
if config == nil {
log.Fatalf(fmt.Sprintf("casbin config is nil"))
}
model := config.Model
//Initialize casbin adapter
adapter, _ := gormadapter.NewAdapterByDB(DB)
// Load model configuration file and policy store adapter
Enforcer, err = casbin.NewEnforcer(model, adapter)
if err != nil {
log.Fatalf(fmt.Sprintf("failed to create casbin enforcer: %v", err))
}
}
到這裡準備工作基本完成，我們來寫一個通用的 登入，註冊，退出 業務吧
user_handler.go
package handler
import (
"fmt"
"github.com/gin-gonic/gin"
"github.com/gin-gonic/gin/binding"
"go-web-demo/component"
"go-web-demo/handler/request"
"go-web-demo/service"
"net/http"
)
func Login(c *gin.Context) {
loginRequest := &request.Login{}
err := c.ShouldBindBodyWith(loginRequest, binding.JSON)
if err != nil {
panic(fmt.Errorf("request body bind error: %v", err))
}
token := service.Login(loginRequest)
c.JSON(http.StatusOK, component.RestResponse{Code: 1, Data: token, Message: loginRequest.Username + " logged in successfully"})
}
func Logout(c *gin.Context) {
token := c.Request.Header.Get("token")
if token == "" {
panic(fmt.Errorf("token error: token is nil"))
}
bytes, err := component.GlobalCache.Get(token)
if err != nil {
panic(fmt.Errorf("token error: failed to get username: %v", err))
}
username := string(bytes)
// Authentication
// Delete store current subject in cache
err = component.GlobalCache.Delete(token)
if err != nil {
panic(fmt.Errorf("failed to delete current subject in cache: %w", err))
}
c.JSON(http.StatusOK, component.RestResponse{Code: 1, Data: token, Message: username + " logout in successfully"})
}
func Register(c *gin.Context) {
register := &request.Register{}
err := c.ShouldBindBodyWith(register, binding.JSON)
if err != nil {
c.JSON(400, component.RestResponse{Code: -1, Message: " bind error"})
return
}
service.Register(register)
c.JSON(http.StatusOK, component.RestResponse{Code: 1, Data: nil, Message: "register successfully"})
}
service.user.go
這裡要注意 註冊的時候我們做了兩個操作，註冊到user表，把policy寫入到casbin_rule表，要保證他們要同時成功，所以要用事務
func Login(loginRequest *request.Login) string {
password := loginRequest.Password
username := loginRequest.Username
// Authentication
user := dao.GetByUsername(username)
if password != user.Password {
panic(fmt.Errorf(username + " logged error : password error"))
}
// Generate random uuid token
u, err := uuid.NewRandom()
if err != nil {
panic(fmt.Errorf("failed to generate UUID: %w", err))
}
// Sprintf token
token := fmt.Sprintf("%s-%s", u.String(), "token")
// Store current subject in cache
err = component.GlobalCache.Set(token, []byte(username))
if err != nil {
panic(fmt.Errorf("failed to store current subject in cache: %w", err))
}
// Send cache key back to client cookie
//c.SetCookie("current_subject", token, 30*60, "/resource", "", false, true)
return token
}
func Register(register *request.Register) {
var err error
e := component.Enforcer
err = e.GetAdapter().(*gormadapter.Adapter).Transaction(e, func(copyEnforcer casbin.IEnforcer) error {
// Insert to table
db := copyEnforcer.GetAdapter().(*gormadapter.Adapter).GetDb()
res := db.Exec("insert into user (username,password) values(?,?)", register.Username, register.Password)
//User has Username and Password
//res := db.Table("user").Create(&User{
// Username: register.Username,
// Password: register.Password,
//})
if err != nil || res.RowsAffected < 1 {
return fmt.Errorf("insert error: %w", err)
}
_, err = copyEnforcer.AddRoleForUser(register.Username, "role::user")
if err != nil {
return fmt.Errorf("add plocy error: %w", err)
}
return nil
})
if err != nil {
panic(err)
}
}
dao.user.go 對資料庫的操作
package dao
import "go-web-demo/component"
type User struct {
Id int64 `gorm:"primaryKey"`
Username string
Password string
Email string
Phone string
}
func (u *User) TableName() string {
return "user"
}
func GetByUsername(username string) *User {
res := new(User)
component.DB.Model(&User{}).Where("username = ?", username).First(res)
return res
}
func Insert(username string, password string) (int64, error, int64) {
user := &User{Username: username, Password: password}
res := component.DB.Create(&user)
return user.Id, res.Error, res.RowsAffected
}
最後一步，啟動web服務，設定路由
package main
import (
"fmt"
"github.com/gin-contrib/cors"
"github.com/gin-gonic/gin"
"go-web-demo/component"
"go-web-demo/config"
"go-web-demo/handler"
"go-web-demo/middleware"
"log"
)
var (
router *gin.Engine
)
func init() {
//Initialize components from config yaml: mysql locaCache casbin
component.CreateByConfig()
// Initialize gin engine
router = gin.Default()
// Initialize gin middleware
corsConfig := cors.DefaultConfig()
corsConfig.AllowAllOrigins = true
corsConfig.AllowCredentials = true
router.Use(cors.New(corsConfig))
router.Use(middleware.Recover)
// Initialize gin router
user := router.Group("/user")
{
user.POST("/login", handler.Login)
user.POST("/logout", handler.Logout)
user.POST("/register", handler.Register)
}
resource := router.Group("/api")
{
resource.Use(middleware.DefaultAuthorize("user::resource", "read-write"))
resource.GET("/resource", handler.ReadResource)
resource.POST("/resource", handler.WriteResource)
}
}
func main() {
// Start
port := config.Reader.Server.Port
err := router.Run(":" + port)
if err != nil {
panic(fmt.Sprintf("failed to start gin engine: %v", err))
}
log.Println("application is now running...")
}
表結構和相關測試資料
CREATE DATABASE /*!32312 IF NOT EXISTS*/`casbin_demo` /*!40100 DEFAULT CHARACTER SET utf8 */;
USE `casbin_demo`;
/*Table structure for table `casbin_rule` */
DROP TABLE IF EXISTS `casbin_rule`;
CREATE TABLE `casbin_rule` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`ptype` varchar(100) NOT NULL,
`v0` varchar(100) DEFAULT NULL,
`v1` varchar(100) DEFAULT NULL,
`v2` varchar(100) DEFAULT NULL,
`v3` varchar(100) DEFAULT NULL,
`v4` varchar(100) DEFAULT NULL,
`v5` varchar(100) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `idx_casbin_rule` (`v0`,`v1`,`v2`,`v3`,`v4`,`v5`)
) ENGINE=InnoDB AUTO_INCREMENT=64 DEFAULT CHARSET=utf8;
/*Data for the table `casbin_rule` */
insert into `casbin_rule`(`id`,`ptype`,`v0`,`v1`,`v2`,`v3`,`v4`,`v5`) values
(3,'p','role::admin','admin::resource','read-write','','',''),
(5,'p','role::user','user::resource','read-write','','',''),
(57,'g','test1','role::user','','','',''),
(59,'g','role::admin','role::user','','','',''),
(63,'g','test2','role::admin',NULL,NULL,NULL,NULL);
/*Table structure for table `user` */
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(50) DEFAULT NULL,
`password` varchar(50) DEFAULT NULL,
`email` varchar(50) DEFAULT NULL,
`phone` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=39 DEFAULT CHARSET=utf8;
/*Data for the table `user` */
insert into `user`(`id`,`username`,`password`,`email`,`phone`) values
(36,'test1','123',NULL,NULL),
(38,'test2','123',NULL,NULL);