func notifyReload() {
pid_b, err := utils.ReadFile(PID_FILE)
if err != nil {
log.Fatalln("Error reading the file of this process id:", err)
}
pid_s := string(pid_b)
log.Debug("This process id is ", pid_s)
if strings.TrimSpace(pid_s) == "" {
log.Fatalln("The file of this process id is empty.")
}
pid, err := strconv.Atoi(pid_s)
if err != nil {
log.Fatalf("String to int error: %s", err)
}
_, err = utils.ExecCommand(false, "kill", "-HUP", pid_s)
if err != nil {
log.Fatalf("Execute commmand <kill -HUP %s> error: %s", pid_s, err)
}
err = syscall.Kill(pid, syscall.SYS_READ)
if err != nil {
log.Fatalf("Kill signal send failed. Pid: %s, error: %s", pid_s, err)
} else {
log.Info("Configuration file is reloading...")
}
}
func main() {
flag.Parse()
if *versionFlag {
fmt.Println(VERSION)
os.Exit(0)
}
if *logstashFlag {
log.ChangeToLogstashFormater(APP_NAME)
}
log.SetLogFile(LOG_FILE)
if *reloadFlag {
notifyReload()
os.Exit(0)
}
pid := os.Getpid() // This process's pid.
log.Infof("The process id is %d", pid)
// Save the pid into the pid file.
err := utils.WriteFile(PID_FILE, []byte(strconv.Itoa(pid)), 0644)
if err != nil {
log.Fatalln("Error writing this process id:", err)
}
defer os.Remove(PID_FILE)
publisher := outputs.NewPublisherType()
taskManager := fetch.NewTaskManager(publisher)
if !reloadConfig(*cfgFileFlag, publisher, taskManager) {
os.Exit(1)
}
// Wait for receive a singal to reload configuration file.
hupCh := make(chan os.Signal)
hupReady := make(chan bool)
signal.Notify(hupCh, syscall.SIGHUP)
go func() {
<-hupReady
for range hupCh {
reloadConfig(*cfgFileFlag, publisher, taskManager)
}
}()
go taskManager.Run()
defer taskManager.Stop()
defer publisher.StopPublish()
close(hupReady)
// Wait for quit signal to exit this process.
sigCh := make(chan os.Signal)
signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM, os.Kill, syscall.SIGKILL)
select {
case s := <-sigCh: // Block until a signal is received.
log.Warnf("Caught Signal: %v, shuting down gracefully...", s)
}
close(hupCh)
log.Info("See you again!")
return
}