🐛 pkg/certwatcher: Start should retry for 10s when adding files

pkg/certwatcher/certwatcher.go

@@ -19,9 +19,14 @@ package certwatcher
 import (
 	"context"
 	"crypto/tls"
+	"fmt"
 	"sync"
+	"time"
 
 	"github.com/fsnotify/fsnotify"
+	kerrors "k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"sigs.k8s.io/controller-runtime/pkg/certwatcher/metrics"
 	logf "sigs.k8s.io/controller-runtime/pkg/internal/log"
 )
@@ -72,11 +77,24 @@ func (cw *CertWatcher) GetCertificate(_ *tls.ClientHelloInfo) (*tls.Certificate,
 
 // Start starts the watch on the certificate and key files.
 func (cw *CertWatcher) Start(ctx context.Context) error {
-	files := []string{cw.certPath, cw.keyPath}
-
-	for _, f := range files {
-		if err := cw.watcher.Add(f); err != nil {
-			return err
+	files := sets.New(cw.certPath, cw.keyPath)
+
+	{
+		ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+		defer cancel()
+		var watchErr error
+		if err := wait.PollImmediateUntilWithContext(ctx, 1*time.Second, func(ctx context.Context) (done bool, err error) {
+			for _, f := range files.UnsortedList() {
+				if err := cw.watcher.Add(f); err != nil {
+					watchErr = err
+					return false, nil //nolint:nilerr // We want to keep trying.
+				}
+				// We've added the watch, remove it from the set.
+				files.Delete(f)
+			}
+			return true, nil
+		}); err != nil {
+			return fmt.Errorf("failed to add watches: %w", kerrors.NewAggregate([]error{err, watchErr}))
 		}
 	}
 
@@ -154,13 +172,13 @@ func (cw *CertWatcher) handleEvent(event fsnotify.Event) {
 }
 
 func isWrite(event fsnotify.Event) bool {
-	return event.Op&fsnotify.Write == fsnotify.Write
+	return event.Op.Has(fsnotify.Write)
 }
 
 func isCreate(event fsnotify.Event) bool {
-	return event.Op&fsnotify.Create == fsnotify.Create
+	return event.Op.Has(fsnotify.Create)
 }
 
 func isRemove(event fsnotify.Event) bool {
-	return event.Op&fsnotify.Remove == fsnotify.Remove
+	return event.Op.Has(fsnotify.Remove)
 }