[go practical basis] how to customize and use a middleware in gin

Catalog

One 、 brief introduction

Two 、 Knowledge point

gin route

Array of strings

Array loop

Custom middleware

http Status code

3、 ... and 、 Rookie actual combat

1、 establish go file

 2、 Running results

add to get Routing and callback

---

One 、 brief introduction

Actual combat scene : gin How to customize and use a middleware

Two 、 Knowledge point

• gin route

• Array of strings

• Array loop

• Custom middleware

• http Status code

3、 ... and 、 Rookie actual combat

Make arrangements now ！

1、 establish go file

/*
 * @Author:  Rookie actual combat 
 * @Description: gin  How to customize and use a middleware 
 */

//  Knowledge point :
// # gin  route 
// #  Array of strings 
// #  Array loop 
// #  Custom middleware 
// # http  Status code 

package main

//  Import package 
import (
	"fmt"
	"github.com/gin-gonic/gin"
	"runtime"
)

// IP  Authorization middleware 

func IPAuthMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		//  White list 
		whiteIpList := []string{
			"127.0.0.1",
		}

		flag := false

		//  Get the current access  ip,  And white list  ip compare 
		clientIp := c.ClientIP()
		fmt.Printf(" At present  client ip  by : %s \n", clientIp)
		for _, whiteIp := range whiteIpList {
			//  Verification passed 
			if clientIp == whiteIp {
				flag = true
				break
			}
		}

		//  Verification failed 
		if flag == false {
			c.String(401, "client ip % is not in the white ip list", clientIp)
			//  need  abort
			c.Abort()
		}

	}

}

//  The main function 
func main() {
	//  Print using built-in functions 
	println("Hello", " Rookie actual combat ")
	println(" Actual combat scene : ", "gin  How to customize and use a middleware ")

	//  initialization 
	r := gin.Default()

	//  Using middleware 
	r.Use(IPAuthMiddleware())

	//  add to  get  Routing and callback 
	r.GET("/g", func(c *gin.Context) {
		//  Back to  code  and   String returns 
		c.String(200, " This is a method using middleware  \n")
	})

	//  Use package functions to print 
	fmt.Printf(" edition : %s \n", runtime.Version())

	//  Start the framework program ,  Default  8080  port 
	r.Run()

}

// curl  Verification mode 
// bind get
// curl -X GET "http://127.0.0.1:8080/g"

 2、 Running results

Hello Rookie actual combat

Actual combat scene : gin How to customize and use a middleware

[GIN-debug] Listening and serving HTTP on :8080

add to get Routing and callback

Rookie actual combat , Continuous learning !