Golang原生http实现中间件

NPE~2024-06-04 18:00

Golang原生http实现中间件

中间件（middleware）：常被用来做认证校验、审计等

  • 大家常用的Iris、Gin等web框架，都包含了中间件逻辑。但有时我们引入该框架显得较为繁重，本文将介绍通过golang原生http来实现中间件操作。
  • 全部代码：https://github.com/ziyifast/ziyifast-code_instruction/tree/main/middleware

1 定义http.Handler：具体中间件操作

①CORSMiddleware：允许跨域

go 复制代码 
// CORSMiddleware handles Cross-Origin Resource Sharing (CORS) responses.
func CORSMiddleware(next http.Handler) http.Handler {
	fmt.Println("cors middleware....")
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == "OPTIONS" {
			w.Header().Set("Access-Control-Allow-Origin", "*")
			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS, DELETE")
			//如果前后端需要传递自定义请求头，需要再Access-Control-Allow-Headers中匹配(Yi-Auth-Token)
			w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Accept, Yi-Auth-Token")
			w.WriteHeader(http.StatusOK)
			return
		}
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS, DELETE")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type,Accept,Yi-Auth-Token")
		//交给下一个中间件处理
		next.ServeHTTP(w, r)
	})
}

②AuthMiddleware：认证

go 复制代码 
// AuthMiddleware simulates a simple authentication middleware.
func AuthMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Println("auth middleware...")
		//store info in ctx
		token := r.Header.Get("Token")
		if len(token) != 0 {
			//TODO 1. check token 2. get userinfo from token
			userID := "1"
			ctx := context.WithValue(r.Context(), "userID", userID)
			r = r.WithContext(ctx)
		}
		next.ServeHTTP(w, r)
	})
}

③AuditMiddleware：审计操作

go 复制代码 
// AuditMiddleware simulates an audit logging middleware.
func AuditMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Println("audit middleware...")
		next.ServeHTTP(w, r)
	})
}

④SmokeHandler：具体处理操作

go 复制代码 
// SmokeHandler returns the current time as a string.
func SmokeHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Println("smoke handle....")
	_, err := w.Write([]byte(time.Now().String()))
	if err != nil {
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

2 义中间件类型&定义中间件链

①type Middleware func(http.Handler) http.Handler：定义中间件

go 复制代码 
type Middleware func(http.Handler) http.Handler

②定义中间件链MiddlewareChain

go 复制代码 
// NewMiddlewareChain creates a new middleware chain with the given middlewares.
func NewMiddlewareChain(middlewares ...Middleware) Middleware {
	return func(handler http.Handler) http.Handler {
		for i := len(middlewares) - 1; i >= 0; i-- {
			handler = middlewares[i](handler)
		}
		return handler
	}
}

3 启动http服务

go 复制代码 
func RunAndServe() error {
	defer func() {
		if e := recover(); e != nil {
			fmt.Println("err=", e)
		}
	}()

	mux := http.NewServeMux()

	// Create middleware chains for routes.
	authMiddlewareChain := NewMiddlewareChain(CORSMiddleware, AuthMiddleware, AuditMiddleware)
	//noAuthMiddlewareChain := NewMiddlewareChain(CORSMiddleware)

	// Convert the middleware chain result to http.HandlerFunc.
	smokeHandlerWrapped := func(w http.ResponseWriter, r *http.Request) {
		authMiddlewareChain(http.HandlerFunc(SmokeHandler)).ServeHTTP(w, r)
	}

	mux.HandleFunc("/smoke", smokeHandlerWrapped)

	fmt.Printf("listening on http://localhost:%d\n", 9999)
	return http.ListenAndServe(":9999", mux)
}

4 测试

  1. 启动后端
go 复制代码 
go run main.go

  1. 浏览器访问http://localhost:9999/smoke

  2. 后端日志打印

可以看到是最后才处理我们的业务Handler

全部代码

🚀：https://github.com/ziyifast/ziyifast-code_instruction/tree/main/middleware

go 复制代码 
package main

import (
	"context"
	"fmt"
	"net/http"
	"time"
)

type Middleware func(http.Handler) http.Handler

// CORSMiddleware handles Cross-Origin Resource Sharing (CORS) responses.
func CORSMiddleware(next http.Handler) http.Handler {
	fmt.Println("cors middleware....")
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == "OPTIONS" {
			w.Header().Set("Access-Control-Allow-Origin", "*")
			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS, DELETE")
			//如果前后端需要传递自定义请求头，需要再Access-Control-Allow-Headers中匹配(Yi-Auth-Token)
			w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Accept, Yi-Auth-Token")
			w.WriteHeader(http.StatusOK)
			return
		}
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS, DELETE")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type,Accept,Yi-Auth-Token")
		next.ServeHTTP(w, r)
	})
}

// AuthMiddleware simulates a simple authentication middleware.
func AuthMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Println("auth middleware...")
		//store info in ctx
		token := r.Header.Get("Token")
		if len(token) != 0 {
			//TODO 1. check token 2. get userinfo from token
			userID := "1"
			ctx := context.WithValue(r.Context(), "userID", userID)
			r = r.WithContext(ctx)
		}
		next.ServeHTTP(w, r)
	})
}

// AuditMiddleware simulates an audit logging middleware.
func AuditMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Println("audit middleware...")
		next.ServeHTTP(w, r)
	})
}

// SmokeHandler returns the current time as a string.
func SmokeHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Println("smoke handle....")
	_, err := w.Write([]byte(time.Now().String()))
	if err != nil {
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

// NewMiddlewareChain creates a new middleware chain with the given middlewares.
func NewMiddlewareChain(middlewares ...Middleware) Middleware {
	return func(handler http.Handler) http.Handler {
		for i := len(middlewares) - 1; i >= 0; i-- {
			handler = middlewares[i](handler)
		}
		return handler
	}
}

func RunAndServe() error {
	defer func() {
		if e := recover(); e != nil {
			fmt.Println("err=", e)
		}
	}()

	mux := http.NewServeMux()

	// Create middleware chains for routes.
	authMiddlewareChain := NewMiddlewareChain(CORSMiddleware, AuthMiddleware, AuditMiddleware)
	//noAuthMiddlewareChain := NewMiddlewareChain(CORSMiddleware)

	// Convert the middleware chain result to http.HandlerFunc.
	smokeHandlerWrapped := func(w http.ResponseWriter, r *http.Request) {
		authMiddlewareChain(http.HandlerFunc(SmokeHandler)).ServeHTTP(w, r)
	}

	mux.HandleFunc("/smoke", smokeHandlerWrapped)

	fmt.Printf("listening on http://localhost:%d\n", 9999)
	return http.ListenAndServe(":9999", mux)
}

func main() {
	RunAndServe()
}
相关推荐
不可能的是6 小时前
前端 SSE 流式请求三种实现方案全解析
前端·http
花酒锄作田4 天前
Gin 框架中的规范响应格式设计与实现
golang·gin
YAY_tyy4 天前
2025 最新版 Node.js 下载安装及环境配置教程
前端·node.js·教程·工具配置
SunnyRivers4 天前
LangChain中间件详解
中间件·langchain
古译汉书4 天前
【IoT死磕系列】Day 7：只传8字节怎么控机械臂？学习工业控制 CANopen 的“对象字典”（附企业级源码）
数据结构·stm32·物联网·http
金刚猿4 天前
06_虚拟机中间件部署_xxl-job 部署
中间件·xxl-job·xxl-job-admin
qwfys2004 天前
How to install golang 1.26.0 to Ubuntu 24.04
ubuntu·golang·install
codeejun4 天前
每日一Go-25、Go语言进阶:深入并发模式1
开发语言·后端·golang
石牌桥网管4 天前
Go 泛型（Generics）
服务器·开发语言·golang
21号 14 天前
Http粘包问题回顾
网络·网络协议·http
热门推荐
01GitHub 镜像站点02【OpenClaw 本地实战 Ep.3】突破瓶颈：强制修改 openclaw.json 解锁 32k 上下文记忆03OpenClaw 使用和管理 MCP 完全指南04OpenClaw + 飞书（Feishu）环境搭建指南05OpenClaw优化飞书API 额度已耗尽问题06Claude Code + GLM4.7 避坑指南：解决 Unable to connect to Anthropic services07Clawdbot部署教程：解决‘gateway token missing’授权问题的完整步骤08Window 10部署openclaw报错node.exe : npm error code 12809OpenClaw大龙虾机器人完整安装教程10OpenClaw 接入阿里云百炼 Coding Plan 指南