补充

前言

一些杂七杂八的Gin用法。

优雅重启

默认情况下可以用Ctrl + C或用kill命令直接停止Gin Web应用的进程，可能会导致正在连接的客户端异常。配置优雅重启主要为了正常关闭客户端连接，以及在服务停止前做一些收尾步骤，比如关闭数据库连接等操作。

package main

import (
	"context"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"
)

func f1(c *gin.Context) {
	c.String(http.StatusOK, "hello world")
}

func main() {
	r := gin.Default()
	r.GET("/", f1)
	// r.GET("/user/:name/*action", f2)
	// r.Run("0.0.0.0:8080")
	srv := &http.Server{
		Addr:    "0.0.0.0:8000",
		Handler: r,
	}

	go func() {
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("listen failed, %v\n", err)
		}
	}()

    // 监听系统信号
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, os.Interrupt, syscall.SIGTERM, syscall.SIGINT)
	<-quit
	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		log.Fatalf("server shutdown failed, err: %v\n", err)
	}
	select {
	case <- ctx.Done():
		log.Println("timeout of 3 seconds")
	}
	log.Println("server shutdown")
}

默认日志配置

简单配置

func main() {
    // 禁用控制台颜色，将日志写入文件时不需要控制台颜色。
    gin.DisableConsoleColor()

    // 记录到文件。
    f, _ := os.Create("gin.log")
    gin.DefaultWriter = io.MultiWriter(f)

    // 如果需要同时将日志写入文件和控制台，请使用以下代码。
    // gin.DefaultWriter = io.MultiWriter(f, os.Stdout)

    router := gin.Default()
    router.GET("/ping", func(c *gin.Context) {
        c.String(200, "pong")
    })

    router.Run(":8080")
}

禁用控制台日志

import (
    "io"
    "github.com/gin-gonic/gin"
)

func main(){
    // gin.SetMode(gin.ReleaseMode)
    gin.DefaultWriter = io.Discard
}

获取客户端信息

func f1(c *gin.Context) {
	// 获取客户端IP
	clientIP := c.ClientIP()

	// 获取请求方法
	method := c.Request.Method

	// 获取协议
	proto := c.Request.Proto

	// 获取host
	host := c.Request.Host

	// 请求Path
	path := c.Request.URL.Path

	log.Printf("客户端IP: %s, 请求方法: %s, 协议: %s, host: %s, path: %s", clientIP, method, proto, host, path)

	// 获取请求头
	headers := c.Request.Header
	for hk, hv := range headers {
		log.Printf("header key: %s, value: %s", hk, hv)
	}

	// 获取名为"mycookie"的cookie
	var cookies []string
	cookie, err := c.Cookie("mycookie")
	if err != nil {
		log.Printf("get cookie [mycookie] error: %s", err)
	} else {
		log.Printf("get cookie [mycookie]: %s", cookie)
		cookies = append(cookies, cookie)
	}

	c.JSON(http.StatusOK, gin.H{
		"clientIP": clientIP,
		"method":   method,
		"proto":    proto,
		"host":     host,
		"headers":  headers,
		"cookies":  cookies,
		"path":     path,
	})
}

开启pprof

package main

import (
        "github.com/gin-contrib/pprof"
        "github.com/gin-gonic/gin"
        "net/http"
)

func f1(c *gin.Context) {
        c.String(http.StatusOK, "hello world")
}

func main() {
        r := gin.Default()
        pprof.Register(r)
        r.GET("/", f1)
        r.Run("0.0.0.0:8000")
}

服务起来后，访问：http://127.0.0.1:8000/debug/pprof

多服务多端口

package main

import (
	"log"
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
	"golang.org/x/sync/errgroup"
)

var (
	g errgroup.Group
)

func router01() http.Handler {
	e := gin.New()
	e.Use(gin.Recovery())
	e.GET("/", func(c *gin.Context) {
		c.JSON(
			http.StatusOK,
			gin.H{
				"code":  http.StatusOK,
				"error": "Welcome server 01",
			},
		)
	})

	return e
}

func router02() http.Handler {
	e := gin.New()
	e.Use(gin.Recovery())
	e.GET("/", func(c *gin.Context) {
		c.JSON(
			http.StatusOK,
			gin.H{
				"code":  http.StatusOK,
				"error": "Welcome server 02",
			},
		)
	})

	return e
}

func main() {
	server01 := &http.Server{
		Addr:         ":8080",
		Handler:      router01(),
		ReadTimeout:  5 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	server02 := &http.Server{
		Addr:         ":8081",
		Handler:      router02(),
		ReadTimeout:  5 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	g.Go(func() error {
		return server01.ListenAndServe()
	})

	g.Go(func() error {
		return server02.ListenAndServe()
	})

	if err := g.Wait(); err != nil {
		log.Fatal(err)
	}
}