Merge pull request #117612 from saschagrunert/image-pull-errors

Fix image pull error type `ErrRegistryUnavailable`

pkg/kubelet/cri/remote/remote_image.go

@@ -25,7 +25,9 @@ import (
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"go.opentelemetry.io/otel/trace"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/status"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	tracing "k8s.io/component-base/tracing"
 	"k8s.io/klog/v2"
@@ -165,6 +167,17 @@ func (r *remoteImageService) pullImageV1(ctx context.Context, image *runtimeapi.
 	})
 	if err != nil {
 		klog.ErrorS(err, "PullImage from image service failed", "image", image.Image)
+
+		// We can strip the code from unknown status errors since they add no value
+		// and will make them easier to read in the logs/events.
+		//
+		// It also ensures that checking custom error types from pkg/kubelet/images/types.go
+		// works in `imageManager.EnsureImageExists` (pkg/kubelet/images/image_manager.go).
+		statusErr, ok := status.FromError(err)
+		if ok && statusErr.Code() == codes.Unknown {
+			return "", errors.New(statusErr.Message())
+		}
+
 		return "", err
 	}
 

pkg/kubelet/images/image_manager.go

@@ -157,7 +157,10 @@ func (m *imageManager) EnsureImageExists(ctx context.Context, pod *v1.Pod, conta
 	if imagePullResult.err != nil {
 		m.logIt(ref, v1.EventTypeWarning, events.FailedToPullImage, logPrefix, fmt.Sprintf("Failed to pull image %q: %v", container.Image, imagePullResult.err), klog.Warning)
 		m.backOff.Next(backOffKey, m.backOff.Clock.Now())
-		if imagePullResult.err == ErrRegistryUnavailable {
+
+		// Error assertions via errors.Is is not supported by gRPC (remote runtime) errors right now.
+		// See https://github.com/grpc/grpc-go/issues/3616
+		if imagePullResult.err.Error() == ErrRegistryUnavailable.Error() {
 			msg := fmt.Sprintf("image pull failed for %s because the registry is unavailable.", container.Image)
 			return "", msg, imagePullResult.err
 		}