go doudou应用中使用注解示例详解

go install -v github.com/unionj-cloud/go-doudou@v1.1.9
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go-doudou svc init annotation
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package service

import "context"

//go:generate go-doudou svc http --handler --doc

type Annotation interface {
	// 此接口可公开访问，无需校验登录和权限
	GetGuest(ctx context.Context) (data string, err error)
	// 此接口只有登录用户有权访问
	// @role(USER,ADMIN)
	GetUser(ctx context.Context) (data string, err error)
	// 此接口只有管理员有权访问
	// @role(ADMIN)
	GetAdmin(ctx context.Context) (data string, err error)
}
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package httpsrv

import (
	"net/http"

	ddmodel "github.com/unionj-cloud/go-doudou/framework/http/model"
)

// http handler接口
type AnnotationHandler interface {
	GetGuest(w http.ResponseWriter, r *http.Request)
	GetUser(w http.ResponseWriter, r *http.Request)
	GetAdmin(w http.ResponseWriter, r *http.Request)
}

// 接口路由
func Routes(handler AnnotationHandler) []ddmodel.Route {
	return []ddmodel.Route{
		{
			"GetGuest",
			"GET",
			"/guest",
			handler.GetGuest,
		},
		{
			"GetUser",
			"GET",
			"/user",
			handler.GetUser,
		},
		{
			"GetAdmin",
			"GET",
			"/admin",
			handler.GetAdmin,
		},
	}
}

// 在内存中存储解析出来的注解信息
// ddmodel.AnnotationStore是map[string][]Annotation类型的别名，
// 键是路由名称，值是注解结构体切片。注解结构体中存放了注解名称和参数切片，
// 下文我们实现的校验权限的中间件原理就是通过http.Request对象拿到路由名称，
// 然后用路由名称从RouteAnnotationStore中找出存储的注解结构体切片，
// 最后比对从内存数据源或外部数据源拿到的用户角色和注解结构体的参数切片中的元素
// 判断该用户是否有权限继续访问接口
var RouteAnnotationStore = ddmodel.AnnotationStore{
	"GetUser": {
		{
			Name: "@role",
			Params: []string{
				"USER",
				"ADMIN",
			},
		},
	},
	"GetAdmin": {
		{
			Name: "@role",
			Params: []string{
				"ADMIN",
			},
		},
	},
}
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package httpsrv

import (
	"annotation/vo"
	"github.com/gorilla/mux"
	"github.com/unionj-cloud/go-doudou/toolkit/sliceutils"
	"net/http"
)

// vo.UserStore是map[Auth]RoleEnum的别名类型，键为用户名和密码构成的结构体，值为角色枚举
// 我们用userStore代表数据库
func Auth(userStore vo.UserStore) func(inner http.Handler) http.Handler {
	return func(inner http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// 从http.Request中拿到路由名称
			currentRoute := mux.CurrentRoute(r)
			if currentRoute == nil {
				inner.ServeHTTP(w, r)
				return
			}
			routeName := currentRoute.GetName()
			// 查询该路由是否有关联的注解结构体切片
			// 如果没有，则放行
			if !RouteAnnotationStore.HasAnnotation(routeName, "@role") {
				inner.ServeHTTP(w, r)
				return
			}
			// 从请求头中提取并解析http basic用户名和密码
			user, pass, ok := r.BasicAuth()
			// 如果不成功，则禁止访问，返回401
			if !ok {
				w.Header().Set("WWW-Authenticate", `Basic realm="Provide user name and password"`)
				w.WriteHeader(401)
				w.Write([]byte("Unauthorised.\n"))
				return
			}
			// 从userStore中查询是否存在此用户
			role, exists := userStore[vo.Auth{user, pass}]
			// 如果不存在，则禁止访问，返回401
			if !exists {
				w.Header().Set("WWW-Authenticate", `Basic realm="Provide user name and password"`)
				w.WriteHeader(401)
				w.Write([]byte("Unauthorised.\n"))
				return
			}
			// 如果存在，则判断该接口是否允许该用户所属角色访问
			params := RouteAnnotationStore.GetParams(routeName, "@role")
			// 判断该路由的@role注解的参数切片中是否包含该用户的角色
			// 如果不包含，则禁止访问，返回403
			if !sliceutils.StringContains(params, role.StringGetter()) {
				w.WriteHeader(403)
				w.Write([]byte("Access denied\n"))
				return
			}
			// 如果包含，则放行
			inner.ServeHTTP(w, r)
		})
	}
}
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package main

import (
	service "annotation"
	"annotation/config"
	"annotation/transport/httpsrv"
	"annotation/vo"
	ddhttp "github.com/unionj-cloud/go-doudou/framework/http"
)

func main() {
	conf := config.LoadFromEnv()
	svc := service.NewAnnotation(conf)
	handler := httpsrv.NewAnnotationHandler(svc)
	srv := ddhttp.NewDefaultHttpSrv()
	// 将上文编写的Auth中间件加入go-doudou服务中
	srv.AddMiddleware(httpsrv.Auth(vo.UserStore{
		vo.Auth{
			User: "guest",
			Pass: "guest",
		}: vo.GUEST,
		vo.Auth{
			User: "user",
			Pass: "user",
		}: vo.USER,
		vo.Auth{
			User: "admin",
			Pass: "admin",
		}: vo.ADMIN,
	}))
	srv.AddRoute(httpsrv.Routes(handler)...)
	srv.Run()
}
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go-doudou svc run
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var reAnno = regexp.MustCompile(`@(\S+?)\((.*?)\)`)

func GetAnnotations(text string) []Annotation {
	if !reAnno.MatchString(text) {
		return nil
	}
	var annotations []Annotation
	matches := reAnno.FindAllStringSubmatch(text, -1)
	for _, item := range matches {
		name := fmt.Sprintf(`@%s`, item[1])
		var params []string
		if stringutils.IsNotEmpty(item[2]) {
			params = strings.Split(strings.TrimSpace(item[2]), ",")
		}
		annotations = append(annotations, Annotation{
			Name:   name,
			Params: params,
		})
	}
	return annotations
}
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