func findTask(datastore database.Datastore, renotifyInterval time.Duration, whoAmI string, stopper *utils.Stopper) *database.VulnerabilityNotification { for { // Find a notification to send. notification, err := datastore.GetAvailableNotification(renotifyInterval) if err != nil { // There is no notification or an error occurred. if err != cerrors.ErrNotFound { log.Warningf("could not get notification to send: %s", err) } // Wait. if !stopper.Sleep(checkInterval) { return nil } continue } // Lock the notification. if hasLock, _ := datastore.Lock(notification.Name, whoAmI, lockDuration, false); hasLock { log.Infof("found and locked a notification: %s", notification.Name) return ¬ification } } }
// Run starts the Notifier service. func Run(config *config.NotifierConfig, datastore database.Datastore, 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) for running := true; running; { // Find task. notification := findTask(datastore, config.RenotifyInterval, whoAmI, stopper) if 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 { utils.PrometheusObserveTimeMilliseconds(promNotifierLatencyMilliseconds, notification.Created) datastore.SetNotificationNotified(notification.Name) } if interrupted { running = false } datastore.Unlock(notification.Name, whoAmI) done <- true }() // Refresh task lock until done. outer: for { select { case <-done: break outer case <-time.After(refreshLockDuration): datastore.Lock(notification.Name, whoAmI, lockDuration, true) } } } log.Info("notifier service stopped") }
// Run updates the vulnerability database at regular intervals. func Run(config *config.UpdaterConfig, datastore database.Datastore, st *utils.Stopper) { defer st.End() // Do not run the updater if there is no config or if the interval is 0. if config == nil || config.Interval == 0 { log.Infof("updater service is disabled.") return } whoAmI := uuid.New() log.Infof("updater service started. lock identifier: %s", whoAmI) for { var stop bool // Determine if this is the first update and define the next update time. // The next update time is (last update time + interval) or now if this is the first update. nextUpdate := time.Now().UTC() lastUpdate, firstUpdate, err := getLastUpdate(datastore) if err != nil { log.Errorf("an error occured while getting the last update time") nextUpdate = nextUpdate.Add(config.Interval) } else if firstUpdate == false { nextUpdate = lastUpdate.Add(config.Interval) } // If the next update timer is in the past, then try to update. if nextUpdate.Before(time.Now().UTC()) { // Attempt to get a lock on the the update. log.Debug("attempting to obtain update lock") hasLock, hasLockUntil := datastore.Lock(lockName, whoAmI, lockDuration, false) if hasLock { // Launch update in a new go routine. doneC := make(chan bool, 1) go func() { Update(datastore, firstUpdate) doneC <- true }() for done := false; !done && !stop; { select { case <-doneC: done = true case <-time.After(refreshLockDuration): // Refresh the lock until the update is done. datastore.Lock(lockName, whoAmI, lockDuration, true) case <-st.Chan(): stop = true } } // Unlock the update. datastore.Unlock(lockName, whoAmI) if stop { break } continue } else { lockOwner, lockExpiration, err := datastore.FindLock(lockName) if err != nil { log.Debug("update lock is already taken") nextUpdate = hasLockUntil } else { log.Debugf("update lock is already taken by %s until %v", lockOwner, lockExpiration) nextUpdate = lockExpiration } } } // Sleep, but remain stoppable until approximately the next update time. now := time.Now().UTC() waitUntil := nextUpdate.Add(time.Duration(rand.ExpFloat64()/0.5) * time.Second) log.Debugf("next update attempt scheduled for %v.", waitUntil) if !waitUntil.Before(now) { if !st.Sleep(waitUntil.Sub(time.Now())) { break } } } // Clean resources. for _, metadataFetcher := range metadataFetchers { metadataFetcher.Clean() } for _, fetcher := range fetchers { fetcher.Clean() } log.Info("updater service stopped") }