Method rotate

modules/caddytls/standardstek/stek.go:84–128

rotate rotates keys on a regular basis, sending each updated set of keys down keysChan, until doneChan is closed.

(doneChan <-chan struct{}, keysChan chan<- [][32]byte)

// rotate rotates keys on a regular basis, sending each updated set of
// keys down keysChan, until doneChan is closed.
func (s *standardSTEKProvider) rotate(doneChan <-chan struct{}, keysChan chan<- [][32]byte) {
	defer func() {
		if err := recover(); err != nil {
			log.Printf("[PANIC] standard STEK rotation: %v\n%s", err, debug.Stack())
		}
	}()
	for {
		select {
		case now := <-s.timer.C:
			// copy the slice header to avoid races
			mutex.RLock()
			keysCopy := keys
			mutex.RUnlock()

			// generate a new key, rotating old ones
			var err error
			keysCopy, err = s.stekConfig.RotateSTEKs(keysCopy)
			if err != nil {
				// TODO: improve this handling
				log.Printf("[ERROR] Generating STEK: %v", err)
				continue
			}

			// replace keys slice with updated value and
			// record the timestamp of rotation
			mutex.Lock()
			keys = keysCopy
			lastRotation = now
			mutex.Unlock()

			// send the updated keys to the service
			keysChan <- keysCopy

			// timer channel is already drained, so reset directly (see godoc)
			s.timer.Reset(time.Duration(s.stekConfig.RotationInterval))

		case <-doneChan:
			// again, see godocs for why timer is stopped this way
			if !s.timer.Stop() {
				<-s.timer.C
			}
			return
		}
	}
}

var (
	lastRotation time.Time