main.go

package main

import (
	"context"
	_ "expvar"
	"flag"
	"fmt"
	"gin-template/global"
	"gin-template/internal/model"
	"gin-template/internal/routers"
	"gin-template/pkg/logger"
	"gin-template/pkg/setting"
	"gin-template/pkg/tracer"
	"log"
	"net/http"
	"os"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"
	"gopkg.in/natefinch/lumberjack.v2"
)

var (
	port         string
	runMode      string
	config       string
	isVersion    bool
	buildTime    string
	buildVersion string
	gitCommitID  string
)

func init() {
	err := setupFlag()
	if err != nil {
		log.Fatalf("init.setupFlag err: %v", err)
	}
	err = setupSetting()
	if err != nil {
		log.Fatalf("init.setupSetting err: %v", err)
	}
	err = setupLogger()
	if err != nil {
		log.Fatalf("init.setupLogger err: %v", err)
	}
	err = setupDBEngine()
	if err != nil {
		log.Fatalf("init.setupDBEngine err: %v", err)
	}
	err = setupTracer()
	if err != nil {
		log.Fatalf("init.setupTracer err: %v", err)
	}
}

func main() {
	if isVersion {
		fmt.Printf("buildTime：%s\n", buildTime)
		fmt.Printf("buildVersion：%s\n", buildVersion)
		fmt.Printf("gitCommitID：%s\n", gitCommitID)
		return
	}
	gin.SetMode(global.ServerSetting.RunMode)
	router := routers.NewRouter()
	s := &http.Server{
		Addr:           ":" + global.ServerSetting.HttpPort,
		Handler:        router,
		ReadTimeout:    global.ServerSetting.ReadTimeout,
		WriteTimeout:   global.ServerSetting.WriteTimeout,
		MaxHeaderBytes: 1 << 20,
	}
	go func() {
		err := s.ListenAndServe()
		if err != nil && err != http.ErrServerClosed {
			fmt.Printf("服务启动失败：%v", err)
		}
	}()

	//等待中断信号
	quit := make(chan os.Signal)
	//接受 syscall.SIGINT 和 syscall.SIGTERM
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("Shutting down server...")

	//最大时间控制，用于通知该服务端有5秒的处理时间来处理原来的请求
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := s.Shutdown(ctx); err != nil {
		log.Fatal("Server forced to shutdown:", err)
	}
	log.Println("server exiting...")
}

func setupSetting() error {
	s, err := setting.NewSetting(strings.Split(config, ",")...)
	if err != nil {
		return err
	}
	err = s.ReadSection("Server", &global.ServerSetting)
	if err != nil {
		return err
	}
	err = s.ReadSection("App", &global.AppSetting)
	if err != nil {
		return err
	}
	err = s.ReadSection("Database", &global.DatabaseSetting)
	if err != nil {
		return err
	}
	err = s.ReadSection("JWT", &global.JWTSetting)
	if err != nil {
		return err
	}
	err = s.ReadSection("Email", &global.EmailSetting)
	if err != nil {
		return err
	}
	err = s.ReadSection("Jaeger", &global.JaegerSetting)
	if err != nil {
		return err
	}
	global.JWTSetting.Expire *= time.Second
	global.ServerSetting.ReadTimeout *= time.Second
	global.ServerSetting.WriteTimeout *= time.Second

	if port != "" {
		global.ServerSetting.HttpPort = port
	}
	if runMode != "" {
		global.ServerSetting.RunMode = runMode
	}

	return nil
}

func setupLogger() error {
	fileName := global.AppSetting.LogSavePath + "/" + global.AppSetting.LogFileName + global.AppSetting.LogFileExt
	global.Logger = logger.NewLogger(&lumberjack.Logger{
		Filename:  fileName,
		MaxSize:   500,
		MaxAge:    10,
		LocalTime: true,
	}, "", log.LstdFlags).WithCaller(2)

	return nil
}

func setupDBEngine() error {
	var err error
	global.DBEngine, err = model.NewDBEngine(global.DatabaseSetting)
	if err != nil {
		return err
	}

	return nil
}

func setupTracer() error {
	jaegerTracer, _, err := tracer.NewJaegerTracer(global.AppSetting.ServiceName, global.JaegerSetting.Host)
	if err != nil {
		return err
	}
	global.Tracer = jaegerTracer
	return nil
}

func setupFlag() error {
	flag.StringVar(&port, "port", "", "启动端口")
	flag.StringVar(&runMode, "mode", "", "启动模式")
	flag.StringVar(&config, "config", "configs/", "指定要使用的配置文件路径")
	flag.BoolVar(&isVersion, "version", false, "编译信息")
	flag.Parse()
	return nil
}