Golang学习之平滑重启

overseer

package main

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

  "github.com/jpillora/overseer"
)

//see example.sh for the use-case

// BuildID is compile-time variable
var BuildID = "0"

//convert your 'main()' into a 'prog(state)'
//'prog()' is run in a child process
func prog(state overseer.State) {
  fmt.Printf("app#%s (%s) listening...n", BuildID, state.ID)
  http.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    duration, err := time.ParseDuration(r.FormValue("duration"))
    if err != nil {
      http.Error(w, err.Error(), 400)
      return
    }
    time.Sleep(duration)
    w.Write([]byte("Hello World"))
    fmt.Fprintf(w, "app#%s (%s) says hellon", BuildID, state.ID)
  }))
  http.Serve(state.Listener, nil)
  fmt.Printf("app#%s (%s) exiting...n", BuildID, state.ID)
}

//then create another 'main' which runs the upgrades
//'main()' is run in the initial process
func main() {
  overseer.Run(overseer.Config{
    Program: prog,
    Addresses: []string{":5005", ":5006"},
    //Fetcher: &fetcher.File{Path: "my_app_next"},
    Debug:  false, //display log of overseer actions
  })
}

# 第一次构建项目
go build grace.go
# 运行项目，这时就可以做内容修改了
./grace &
# 请求项目，60s后返回
curl "http://127.0.0.1:5001/sleep?duration=60s" &
# 再次构建项目，这里是新内容
go build grace.go
# 重启，2096为pid
kill -USR2 2096
# 新API请求
curl "http://127.0.0.1:5001/sleep?duration=1s"


# 第一次构建项目
go build endless.go
# 运行项目，这时就可以做内容修改了
./endless &
# 请求项目，60s后返回
curl "http://127.0.0.1:5003/sleep?duration=60s" &
# 再次构建项目，这里是新内容
go build endless.go
# 重启，22072为pid
kill -1 22072
# 新API请求
curl "http://127.0.0.1:5003/sleep?duration=1s"


# 第一次构建项目
go build -ldflags '-X main.BuildID=1' overseer.go
# 运行项目，这时就可以做内容修改了
./overseer &
# 请求项目，60s后返回
curl "http://127.0.0.1:5005/sleep?duration=60s" &
# 再次构建项目，这里是新内容，注意版本号不同了
go build -ldflags '-X main.BuildID=2' overseer.go
# 重启，28300为主进程pid
kill -USR2 28300
# 新API请求
curl http://127.0.0.1:5005/sleep?duration=1s