启动流程
先来看看Go的import逻辑，因为Beego（或者其他Go语言项目）的启动流程都依赖于import的逻辑。
在Bee工具生成的Beego项目目录中，main.go文件内容如下所示：
package main
import (
_ "hello/routers"
"github.com/astaxie/beego"
)
func main() {
beego.Run()
}
routers/router.go内容：
package routers
import (
"hello/controllers"
"github.com/astaxie/beego"
)
func init() {
beego.Router("/", &controllers.MainController{})
}
从代码直观来看，一个Beego应用的启动流程如下：
- 引入beego包
- 注册路由
- 执行beego包的Run方法
从Beego本身的工程目录可以看到，属于包beego的文件有很多，其中Run方法在文件beego.go中，方法定义如下：
// Run beego application.
// beego.Run() default run on HttpPort
// beego.Run("localhost")
// beego.Run(":8089")
// beego.Run("127.0.0.1:8089")
func Run(params ...string) {
initBeforeHTTPRun()
if len(params) > 0 && params[0] != "" {
strs := strings.Split(params[0], ":")
if len(strs) > 0 && strs[0] != "" {
BConfig.Listen.HTTPAddr = strs[0]
}
if len(strs) > 1 && strs[1] != "" {
BConfig.Listen.HTTPPort, _ = strconv.Atoi(strs[1])
}
}
BeeApp.Run()
}
其中 initBeforeHttpRun() 实现如下：
func initBeforeHTTPRun() {
// if AppConfigPath is setted or conf/app.conf exist
err := ParseConfig()
if err != nil {
panic(err)
}
//init log
for adaptor, config := range BConfig.Log.Outputs {
err = BeeLogger.SetLogger(adaptor, config)
if err != nil {
fmt.Printf("%s with the config `%s` got err:%s\n", adaptor, config, err)
}
}
SetLogFuncCall(BConfig.Log.FileLineNum)
//init hooks
AddAPPStartHook(registerMime)
AddAPPStartHook(registerDefaultErrorHandler)
AddAPPStartHook(registerSession)
AddAPPStartHook(registerDocs)
AddAPPStartHook(registerTemplate)
AddAPPStartHook(registerAdmin)
for _, hk := range hooks {
if err := hk(); err != nil {
panic(err)
}
}
}
BeeApp.Run 一句中的BeeApp来自 config.go 文件的 init 方法，调用 NewApp() 来初始化：
// NewApp returns a new beego application.
func NewApp() *App {
// 这玩意比较关键，所有的路由全在里面了
cr := NewControllerRegister()
app := &App{Handlers: cr, Server: &http.Server{}}
return app
}
BeeApp.Run 实现如下所示：
// Run beego application.
func (app *App) Run() {
addr := BConfig.Listen.HTTPAddr
if BConfig.Listen.HTTPPort != 0 {
addr = fmt.Sprintf("%s:%d", BConfig.Listen.HTTPAddr, BConfig.Listen.HTTPPort)
}
var (
err error
l net.Listener
endRunning = make(chan bool, 1)
)
// run cgi server
if BConfig.Listen.EnableFcgi {
if BConfig.Listen.EnableStdIo {
// app.Handlers
if err = fcgi.Serve(nil, app.Handlers); err == nil { // standard I/O
BeeLogger.Info("Use FCGI via standard I/O")
} else {
BeeLogger.Critical("Cannot use FCGI via standard I/O", err)
}
return
}
if BConfig.Listen.HTTPPort == 0 {
// remove the Socket file before start
if utils.FileExists(addr) {
os.Remove(addr)
}
l, err = net.Listen("unix", addr)
} else {
l, err = net.Listen("tcp", addr)
}
if err != nil {
BeeLogger.Critical("Listen: ", err)
}
if err = fcgi.Serve(l, app.Handlers); err != nil {
BeeLogger.Critical("fcgi.Serve: ", err)
}
return
}
app.Server.Handler = app.Handlers
app.Server.ReadTimeout = time.Duration(BConfig.Listen.ServerTimeOut) * time.Second
app.Server.WriteTimeout = time.Duration(BConfig.Listen.ServerTimeOut) * time.Second
// run graceful mode
if BConfig.Listen.Graceful {
httpsAddr := BConfig.Listen.HTTPSAddr
app.Server.Addr = httpsAddr
if BConfig.Listen.EnableHTTPS {
go func() {
time.Sleep(20 * time.Microsecond)
if BConfig.Listen.HTTPSPort != 0 {
httpsAddr = fmt.Sprintf("%s:%d", BConfig.Listen.HTTPSAddr, BConfig.Listen.HTTPSPort)
app.Server.Addr = httpsAddr
}
server := grace.NewServer(httpsAddr, app.Handlers)
server.Server.ReadTimeout = app.Server.ReadTimeout
server.Server.WriteTimeout = app.Server.WriteTimeout
if err := server.ListenAndServeTLS(BConfig.Listen.HTTPSCertFile, BConfig.Listen.HTTPSKeyFile); err != nil {
BeeLogger.Critical("ListenAndServeTLS: ", err, fmt.Sprintf("%d", os.Getpid()))
time.Sleep(100 * time.Microsecond)
endRunning <- true
}
}()
}
if BConfig.Listen.EnableHTTP {
go func() {
server := grace.NewServer(addr, app.Handlers)
server.Server.ReadTimeout = app.Server.ReadTimeout
server.Server.WriteTimeout = app.Server.WriteTimeout
if BConfig.Listen.ListenTCP4 {
server.Network = "tcp4"
}
if err := server.ListenAndServe(); err != nil {
BeeLogger.Critical("ListenAndServe: ", err, fmt.Sprintf("%d", os.Getpid()))
time.Sleep(100 * time.Microsecond)
endRunning <- true
}
}()
}
<-endRunning
return
}
// run normal mode
app.Server.Addr = addr
if BConfig.Listen.EnableHTTPS {
go func() {
time.Sleep(20 * time.Microsecond)
if BConfig.Listen.HTTPSPort != 0 {
app.Server.Addr = fmt.Sprintf("%s:%d", BConfig.Listen.HTTPSAddr, BConfig.Listen.HTTPSPort)
}
BeeLogger.Info("https server Running on %s", app.Server.Addr)
if err := app.Server.ListenAndServeTLS(BConfig.Listen.HTTPSCertFile, BConfig.Listen.HTTPSKeyFile); err != nil {
BeeLogger.Critical("ListenAndServeTLS: ", err)
time.Sleep(100 * time.Microsecond)
endRunning <- true
}
}()
}
if BConfig.Listen.EnableHTTP {
go func() {
app.Server.Addr = addr
BeeLogger.Info("http server Running on %s", app.Server.Addr)
if BConfig.Listen.ListenTCP4 {
ln, err := net.Listen("tcp4", app.Server.Addr)
if err != nil {
BeeLogger.Critical("ListenAndServe: ", err)
time.Sleep(100 * time.Microsecond)
endRunning <- true
return
}
if err = app.Server.Serve(ln); err != nil {
BeeLogger.Critical("ListenAndServe: ", err)
time.Sleep(100 * time.Microsecond)
endRunning <- true
return
}
} else {
if err := app.Server.ListenAndServe(); err != nil {
BeeLogger.Critical("ListenAndServe: ", err)
time.Sleep(100 * time.Microsecond)
endRunning <- true
}
}
}()
}
<-endRunning
}
对于三种服务启动方式，这三种方式都要求app.Handlers实现了http.Handler接口：
type Handler interface {
ServeHTTP(ResponseWriter, *Request)
}