// Run pops notifications from the database, lock them, send them, mark them as
// send and unlock them
//
// It uses an exponential backoff when POST requests fail
func (notifier *HTTPNotifier) Run(st *utils.Stopper) {
defer st.End()
whoAmI := uuid.New()
log.Infof("HTTP notifier started. URL: %s. Lock Identifier: %s", notifier.url, whoAmI)
for {
node, notification, err := database.FindOneNotificationToSend(database.GetDefaultNotificationWrapper())
if notification == nil || err != nil {
if err != nil {
log.Warningf("could not get notification to send: %s.", err)
}
if !st.Sleep(checkInterval) {
break
}
continue
}
// Try to lock the notification
hasLock, hasLockUntil := database.Lock(node, lockDuration, whoAmI)
if !hasLock {
continue
}
for backOff := time.Duration(0); ; backOff = timeutil.ExpBackoff(backOff, maxBackOff) {
// Backoff, it happens when an error occurs during the communication
// with the notification endpoint
if backOff > 0 {
// Renew lock before going to sleep if necessary
if time.Now().Add(backOff).After(hasLockUntil.Add(-refreshLockAnticipation)) {
hasLock, hasLockUntil = database.Lock(node, lockDuration, whoAmI)
if !hasLock {
log.Warning("lost lock ownership, aborting")
break
}
}
// Sleep
if !st.Sleep(backOff) {
return
}
}
// Get notification content
content, err := notification.GetContent()
if err != nil {
log.Warningf("could not get content of notification '%s': %s", notification.GetName(), err.Error())
break
}
// Marshal the notification content
jsonContent, err := json.Marshal(struct {
Name, Type string
Content interface{}
}{
Name: notification.GetName(),
Type: notification.GetType(),
Content: content,
})
if err != nil {
log.Errorf("could not marshal content of notification '%s': %s", notification.GetName(), err.Error())
break
}
// Post notification
req, _ := http.NewRequest("POST", notifier.url, bytes.NewBuffer(jsonContent))
req.Header.Set("Content-Type", "application/json")
client := &http.Client{}
res, err := client.Do(req)
if err != nil {
log.Warningf("could not post notification '%s': %s", notification.GetName(), err.Error())
continue
}
res.Body.Close()
if res.StatusCode != 200 && res.StatusCode != 201 {
log.Warningf("could not post notification '%s': got status code %d", notification.GetName(), res.StatusCode)
continue
}
// Mark the notification as sent
database.MarkNotificationAsSent(node)
log.Infof("sent notification '%s' successfully", notification.GetName())
break
}
if hasLock {
database.Unlock(node, whoAmI)
}
}
log.Info("HTTP notifier stopped")
}
// Run starts the Notifier service.
func Run(config *config.NotifierConfig, stopper *utils.Stopper) {
defer stopper.End()
// Configure registered notifiers.
for notifierName, notifier := range notifiers {
if configured, err := notifier.Configure(config); configured {
log.Infof("notifier '%s' configured\n", notifierName)
} else {
delete(notifiers, notifierName)
if err != nil {
log.Errorf("could not configure notifier '%s': %s", notifierName, err)
}
}
}
// Do not run the updater if there is no notifier enabled.
if len(notifiers) == 0 {
log.Infof("notifier service is disabled")
return
}
whoAmI := uuid.New()
log.Infof("notifier service started. lock identifier: %s\n", whoAmI)
// Register healthchecker.
health.RegisterHealthchecker("notifier", Healthcheck)
for running := true; running; {
// Find task.
// TODO(Quentin-M): Combine node and notification.
node, notification := findTask(whoAmI, stopper)
if node == "" && notification == nil {
// Interrupted while finding a task, Clair is stopping.
break
}
// Handle task.
done := make(chan bool, 1)
go func() {
success, interrupted := handleTask(notification, stopper, config.Attempts)
if success {
database.MarkNotificationAsSent(node)
}
if interrupted {
running = false
}
database.Unlock(node, whoAmI)
done <- true
}()
// Refresh task lock until done.
outer:
for {
select {
case <-done:
break outer
case <-time.After(refreshLockDuration):
database.Lock(node, lockDuration, whoAmI)
}
}
}
log.Info("notifier service stopped")
}