🌱 Source should retry to get informers until timeout expires

Signed-off-by: Vince Prignano <[email protected]>

Author: vincepri

pkg/source/source.go

@@ -21,8 +21,10 @@ import (
 	"errors"
 	"fmt"
 	"sync"
+	"time"
 
 	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/util/workqueue"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/event"
@@ -119,17 +121,34 @@ func (ks *Kind) Start(ctx context.Context, handler handler.EventHandler, queue w
 	ctx, ks.startCancel = context.WithCancel(ctx)
 	ks.started = make(chan error)
 	go func() {
-		// Lookup the Informer from the Cache and add an EventHandler which populates the Queue
-		i, err := ks.cache.GetInformer(ctx, ks.Type)
-		if err != nil {
-			kindMatchErr := &meta.NoKindMatchError{}
-			if errors.As(err, &kindMatchErr) {
-				log.Error(err, "if kind is a CRD, it should be installed before calling Start",
-					"kind", kindMatchErr.GroupKind)
+		var (
+			i       cache.Informer
+			lastErr error
+		)
+
+		// Tries to get an informer until it returns true,
+		// an error or the specified context is cancelled or expired.
+		if err := wait.PollImmediateUntilWithContext(ctx, 10*time.Second, func(ctx context.Context) (bool, error) {
+			// Lookup the Informer from the Cache and add an EventHandler which populates the Queue
+			i, lastErr = ks.cache.GetInformer(ctx, ks.Type)
+			if lastErr != nil {
+				kindMatchErr := &meta.NoKindMatchError{}
+				if errors.As(lastErr, &kindMatchErr) {
+					log.Error(lastErr, "if kind is a CRD, it should be installed before calling Start",
+						"kind", kindMatchErr.GroupKind)
+				}
+				return false, nil // Retry.
+			}
+			return true, nil
+		}); err != nil {
+			if lastErr != nil {
+				ks.started <- fmt.Errorf("failed to get informer from cache: %w", lastErr)
+				return
 			}
 			ks.started <- err
 			return
 		}
+
 		i.AddEventHandler(internal.EventHandler{Queue: queue, EventHandler: handler, Predicates: prct})
 		if !ks.cache.WaitForCacheSync(ctx) {
 			// Would be great to return something more informative here