// Run updates the vulnerability database at regular intervals
func Run(interval time.Duration, st *utils.Stopper) {
defer st.End()
// Do not run the updater if the interval is 0
if interval == 0 {
log.Infof("updater service is disabled.")
return
}
whoAmI := uuid.New()
healthIdentifier = whoAmI
log.Infof("updater service started. lock identifier: %s", whoAmI)
for {
// Set the next update time to (last update time + interval) or now if there
// is no last update time stored in database (first update) or if an error
// occurs
nextUpdate := time.Now().UTC()
if lastUpdateTSS, err := database.GetFlagValue(flagName); err == nil && lastUpdateTSS != "" {
if lastUpdateTS, err := strconv.ParseInt(lastUpdateTSS, 10, 64); err == nil {
healthLatestSuccessfulUpdate = time.Unix(lastUpdateTS, 0)
nextUpdate = time.Unix(lastUpdateTS, 0).Add(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 := database.Lock(flagName, lockDuration, whoAmI)
if hasLock {
healthLockOwner = healthIdentifier
// Launch update in a new go routine.
doneC := make(chan bool, 1)
go func() {
Update()
doneC <- true
}()
for done := false; !done; {
select {
case <-doneC:
done = true
case <-time.After(refreshLockDuration):
// Refresh the lock until the update is done.
database.Lock(flagName, lockDuration, whoAmI)
}
}
// Unlock the update.
database.Unlock(flagName, whoAmI)
} else {
lockOwner, lockExpiration, err := database.LockInfo(flagName)
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
healthLockOwner = lockOwner
}
}
}
// 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
}
}
}
log.Info("updater service stopped")
}
// Run updates the vulnerability database at regular intervals.
func Run(config *config.UpdaterConfig, 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
}
// Register healthchecker.
health.RegisterHealthchecker("updater", Healthcheck)
whoAmI := uuid.New()
log.Infof("updater service started. lock identifier: %s", whoAmI)
for {
// Set the next update time to (last update time + interval) or now if there
// is no last update time stored in database (first update) or if an error
// occurs.
var nextUpdate time.Time
var stop bool
if lastUpdate := getLastUpdate(); !lastUpdate.IsZero() {
nextUpdate = lastUpdate.Add(config.Interval)
} else {
nextUpdate = time.Now().UTC()
}
// 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 := database.Lock(flagName, lockDuration, whoAmI)
if hasLock {
// Launch update in a new go routine.
doneC := make(chan bool, 1)
go func() {
Update()
doneC <- true
}()
for done := false; !done && !stop; {
select {
case <-doneC:
done = true
case <-time.After(refreshLockDuration):
// Refresh the lock until the update is done.
database.Lock(flagName, lockDuration, whoAmI)
case <-st.Chan():
stop = true
}
}
// Unlock the update.
database.Unlock(flagName, whoAmI)
if stop {
break
}
continue
} else {
lockOwner, lockExpiration, err := database.LockInfo(flagName)
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
}
}
}
log.Info("updater service stopped")
}
