fix: send datasync on remove fs events (#339)

Looks like during a refactor, we accidentally removed the "meat" of the
remove handler.

In K8S, we never get write events, just remove. It's necessary to send
the data for these as well.

Also extracted some duplicated code into a func.

---------

Signed-off-by: Todd Baert <toddbaert@gmail.com>

pkg/sync/file/filepath_sync.go

@@ -58,25 +58,13 @@ func (fs *Sync) Sync(ctx context.Context, dataSync chan<- sync.DataSync) error {
 			fs.Logger.Info(fmt.Sprintf("Filepath event: %s %s", event.Name, event.Op.String()))
 
 			switch event.Op {
-			case fsnotify.Create:
-				fs.Logger.Debug("New configuration created")
-				msg, err := fs.fetch(ctx)
-				if err != nil {
-					fs.Logger.Error(fmt.Sprintf("Error fetching after Create notification: %s", err.Error()))
-					continue
-				}
-
-				dataSync <- sync.DataSync{FlagData: msg, Source: fs.URI}
-			case fsnotify.Write:
-				fs.Logger.Debug("Configuration modified")
-				msg, err := fs.fetch(ctx)
-				if err != nil {
-					fs.Logger.Error(fmt.Sprintf("Error fetching after Write notification: %s", err.Error()))
-					continue
-				}
-
-				dataSync <- sync.DataSync{FlagData: msg, Source: fs.URI}
+			case fsnotify.Create, fsnotify.Write:
+				fs.sendDataSync(ctx, event, dataSync)
 			case fsnotify.Remove:
+				// Counterintuively, remove events are the only meanful ones seen in K8s.
+				// At the point the remove event is fired, we have our new data, so we can send it down the channel.
+				fs.sendDataSync(ctx, event, dataSync)
+
 				// K8s exposes config maps as symlinks.
 				// Updates cause a remove event, we need to re-add the watcher in this case.
 				err = watcher.Add(fs.URI)
@@ -97,6 +85,16 @@ func (fs *Sync) Sync(ctx context.Context, dataSync chan<- sync.DataSync) error {
 	}
 }
 
+func (fs *Sync) sendDataSync(ctx context.Context, eventType fsnotify.Event, dataSync chan<- sync.DataSync) {
+	fs.Logger.Debug(fmt.Sprintf("Configuration %s: %s", fs.URI, eventType.Op.String()))
+	msg, err := fs.fetch(ctx)
+	if err != nil {
+		fs.Logger.Error(fmt.Sprintf("Error fetching after %s notification: %s", eventType.Op.String(), err.Error()))
+	}
+
+	dataSync <- sync.DataSync{FlagData: msg, Source: fs.URI}
+}
+
 func (fs *Sync) fetch(_ context.Context) (string, error) {
 	if fs.URI == "" {
 		return "", errors.New("no filepath string set")