[9.2](backport #45944) chore: fix formatting issues in logp printf-style calls

libbeat/processors/add_host_metadata/add_host_metadata.go

@@ -112,6 +112,31 @@
 		p.geoData = mapstr.M{"host": mapstr.M{"geo": geoFields}}
 	}
 
+<<<<<<< HEAD
+=======
+	// create a unique ID for this instance of the processor
+	var cbIDStr string
+	cbID, err := uuid.NewV4()
+	// if we fail, fall back to the processor name, hope for the best.
+	if err != nil {
+		p.logger.Errorf("error generating ID for FQDN callback, reverting to processor name: %v", err)
+		cbIDStr = processorName
+	} else {
+		cbIDStr = cbID.String()
+	}
+
+	// this is safe as New() returns a pointer, not the actual object.
+	// This matters as other pieces of code in libbeat, like libbeat/processors/processor.go,
+	// will do weird stuff like copy the entire list of global processors.
+	err = features.AddFQDNOnChangeCallback(p.handleFQDNReportingChange, cbIDStr)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"could not register callback for FQDN reporting onChange from %s processor: %w",
+			processorName, err,
+		)
+	}
+
+>>>>>>> a5be2a856 (chore: fix formatting issues in logp printf-style calls (#45944))
 	return p, nil
 }
 
@@ -245,6 +270,63 @@
 		processorName, p.config.NetInfoEnabled, p.config.CacheTTL)
 }
 
+<<<<<<< HEAD
+=======
+func (p *addHostMetadata) handleFQDNReportingChange(new, old bool) {
+	if new == old {
+		// Nothing to do
+		return
+	}
+
+	// update the data for the processor
+	p.updateOrExpire(new)
+}
+
+// updateOrExpire will attempt to update the data for the processor, or expire the cache
+// if the config update fails, or times out
+func (p *addHostMetadata) updateOrExpire(useFQDN bool) {
+	if p.config.CacheTTL <= 0 {
+		return
+	}
+
+	p.lastUpdate.Lock()
+	defer p.lastUpdate.Unlock()
+
+	// while holding the mutex, attempt to update loadData()
+	// doing this with the mutex means other events must wait until we have the correct host data, as we assume that
+	// a call to this function means something else wants to force an update, and thus all events must sync.
+
+	updateChanSuccess := make(chan bool)
+	timeout := time.After(p.config.ExpireUpdateTimeout)
+	go func() {
+		err := p.loadData(false, useFQDN)
+		if err != nil {
+			p.logger.Errorf("error updating data for processor: %v", err)
+			updateChanSuccess <- false
+			return
+		}
+		updateChanSuccess <- true
+	}()
+
+	// this additional timeout check is paranoid, but when it's method is called from handleFQDNReportingChange(),
+	// it's blocking, which means we can hold a mutex in features. In addition, we don't want to break the processor by
+	// having all the events wait for too long.
+	select {
+	case <-timeout:
+		p.logger.Errorf("got timeout while trying to update metadata")
+		p.lastUpdate.Time = time.Time{}
+	case success := <-updateChanSuccess:
+		// only expire the cache if update was failed
+		if !success {
+			p.lastUpdate.Time = time.Time{}
+		} else {
+			p.lastUpdate.Time = time.Now()
+		}
+	}
+
+}
+
+>>>>>>> a5be2a856 (chore: fix formatting issues in logp printf-style calls (#45944))
 func skipAddingHostMetadata(event *beat.Event) bool {
 	// If host fields exist(besides host.name added by libbeat) in event, skip add_host_metadata.
 	hostFields, err := event.Fields.GetValue("host")