// Terminate kills the application
func (a *App) Terminate() {
a.signalLock.Lock()
defer a.signalLock.Unlock()
a.stopPolling()
a.forAllServices(deregisterService)
// Run and wait for preStop command to exit
utils.RunWithFields(a.PreStopCmd, log.Fields{"process": "PreStop"})
cmd := a.Command
if cmd == nil || cmd.Process == nil {
// Not managing the process, so don't do anything
return
}
if a.StopTimeout > 0 {
if err := cmd.Process.Signal(syscall.SIGTERM); err != nil {
log.Warnf("Error sending SIGTERM to application: %s", err)
} else {
time.AfterFunc(time.Duration(a.StopTimeout)*time.Second, func() {
log.Infof("Killing Process %#v", cmd.Process)
cmd.Process.Kill()
})
return
}
}
log.Infof("Killing Process %#v", a.Command.Process)
cmd.Process.Kill()
}
// OnChange runs the backend's onChange command, returning the results
func (b *Backend) OnChange() (int, error) {
defer func() {
// reset command object because it can't be reused
b.onChangeCmd = utils.ArgsToCmd(b.onChangeCmd.Args)
}()
exitCode, err := utils.RunWithFields(b.onChangeCmd, log.Fields{"process": "OnChange", "backend": b.Name})
return exitCode, err
}
// Run starts the application and blocks until finished
func (a *App) Run() {
// Set up handlers for polling and to accept signal interrupts
if 1 == os.Getpid() {
reapChildren()
}
args := getArgs(flag.Args())
command, err := utils.ParseCommandArgs(args)
if err != nil {
log.Errorf("Unable to parse command arguments: %v", err)
}
a.handleSignals()
// Run the preStart handler, if any, and exit if it returns an error
if preStartCode, err := utils.RunWithFields(a.PreStartCmd, log.Fields{"process": "PreStart"}); err != nil {
os.Exit(preStartCode)
}
a.handleCoprocesses()
a.handlePolling()
if len(args) != 0 {
// Run our main application and capture its stdout/stderr.
// This will block until the main application exits and then os.Exit
// with the exit code of that application.
a.Command = command
command.Stderr = os.Stderr
command.Stdout = os.Stdout
code, err := utils.ExecuteAndWait(command)
if err != nil {
log.Println(err)
}
// Run the PostStop handler, if any, and exit if it returns an error
if postStopCode, err := utils.RunWithFields(a.PostStopCmd, log.Fields{"process": "PostStop"}); err != nil {
os.Exit(postStopCode)
}
os.Exit(code)
}
// block forever, as we're polling in the two polling functions and
// did not os.Exit by waiting on an external application.
select {}
}
// CheckHealth runs the service's health command, returning the results
func (s *Service) CheckHealth() (int, error) {
defer func() {
// reset command object because it can't be reused
if s.healthCheckCmd != nil {
s.healthCheckCmd = utils.ArgsToCmd(s.healthCheckCmd.Args)
}
}()
// if we have a valid Service but there's no health check
// set, assume it always passes (ex. telemetry service).
if s.healthCheckCmd == nil {
return 0, nil
}
exitCode, err := utils.RunWithFields(s.healthCheckCmd, log.Fields{"process": "health", "serviceName": s.Name, "serviceID": s.ID})
return exitCode, err
}