overflow_probe_container/server/server_handlers.go

package server

import (
	"fmt"
	"io/ioutil"
	"net"
	"os"
	"path/filepath"
	"strconv"

	"git.loafle.net/commons_go/logging"
	"git.loafle.net/commons_go/server"
)

func NewServerHandler(pidPath string, serverName string, socketHandler SocketHandler) ServerHandler {
	pidPathABS, err := filepath.Abs(pidPath)
	if nil != err {
		logging.Logger().Panicf("Container: pid file path[%s] is not valid %v", pidPath, err)
	}

	sh := &ServerHandlers{
		pidPath:    pidPath,
		pidPathABS: pidPathABS,
	}

	sh.Name = serverName
	sh.SocketHandler = socketHandler
	return sh
}

type ServerHandlers struct {
	server.ServerHandlers

	pidPath    string
	pidPathABS string
	port       int
}

func (sh *ServerHandlers) Init(serverCTX server.ServerContext) error {
	if err := sh.ServerHandlers.Init(serverCTX); nil != err {
		return err
	}

	return nil
}

func (sh *ServerHandlers) Listen(serverCTX server.ServerContext) (net.Listener, error) {
	for i := 60000; i < 61000; i++ {
		addr := fmt.Sprintf("localhost:%d", i)
		l, err := net.Listen("tcp", addr)
		if nil == err {
			sh.port = i
			return l, nil
		}
	}

	return nil, fmt.Errorf("Container: Cannot find availrable port")
}

func (sh *ServerHandlers) OnStart(serverCTX server.ServerContext) {
	sh.ServerHandlers.OnStart(serverCTX)

	if _, err := os.Stat(sh.pidPathABS); os.IsExist(err) {
		if err := os.Remove(sh.pidPathABS); nil != err {
			logging.Logger().Errorf("Container: Removing pid file has been failed [%v]", err)
		}
	}

	s := strconv.FormatInt(int64(sh.port), 10)
	ioutil.WriteFile(sh.pidPathABS, []byte(s), os.ModePerm)
}

func (sh *ServerHandlers) OnStop(serverCTX server.ServerContext) {
	if _, err := os.Stat(sh.pidPathABS); os.IsExist(err) {
		if err := os.Remove(sh.pidPathABS); nil != err {
			logging.Logger().Errorf("Container: Removing pid file has been failed [%v]", err)
		}
	}

	sh.ServerHandlers.OnStop(serverCTX)
}

func (sh *ServerHandlers) Validate() {
	sh.ServerHandlers.Validate()

	if "" == sh.pidPath {
		logging.Logger().Panicf("Container: The path of pid file must be specified")
	}

}