Enhance error messages around image to tag resolving.

pkg/reconciler/revision/resolve.go

@@ -92,7 +92,7 @@ func (r *digestResolver) Resolve(
 	registriesToSkip sets.String) (string, error) {
 	kc, err := k8schain.New(r.client, opt)
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("failed to initialize authentication: %w", err)
 	}
 
 	if _, err := name.NewDigest(image, name.WeakValidation); err == nil {
@@ -102,7 +102,7 @@ func (r *digestResolver) Resolve(
 
 	tag, err := name.NewTag(image, name.WeakValidation)
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("failed to parse image name %q into a tag: %w", image, err)
 	}
 
 	if registriesToSkip.Has(tag.Registry.RegistryStr()) {
@@ -114,7 +114,7 @@ func (r *digestResolver) Resolve(
 	}
 	desc, err := remote.Get(tag, remote.WithTransport(r.transport), remote.WithAuthFromKeychain(kc), remote.WithPlatform(platform))
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("failed to fetch image information: %w", err)
 	}
 
 	// TODO(#3997): Use remote.Get to resolve manifest lists to digests as well
@@ -123,11 +123,11 @@ func (r *digestResolver) Resolve(
 	case types.OCIImageIndex, types.DockerManifestList:
 		img, err := desc.Image()
 		if err != nil {
-			return "", err
+			return "", fmt.Errorf("failed to get image reference: %w", err)
 		}
 		dgst, err := img.Digest()
 		if err != nil {
-			return "", err
+			return "", fmt.Errorf("failed to get image digest: %w", err)
 		}
 		return fmt.Sprintf("%s@%s", tag.Repository.String(), dgst), nil
 	default:

pkg/reconciler/revision/revision.go

@@ -18,6 +18,7 @@ package revision
 
 import (
 	"context"
+	"fmt"
 	"reflect"
 	"strings"
 
@@ -142,6 +143,7 @@ func (c *Reconciler) reconcileDigest(ctx context.Context, rev *v1alpha1.Revision
 	digest, err := c.resolver.Resolve(rev.Spec.GetContainer().Image,
 		opt, cfgs.Deployment.RegistriesSkippingTagResolving)
 	if err != nil {
+		err = fmt.Errorf("failed to resolve image to digest: %w", err)
 		rev.Status.MarkContainerHealthyFalse(v1alpha1.ContainerMissing,
 			v1alpha1.RevisionContainerMissingMessage(
 				rev.Spec.GetContainer().Image, err.Error()))

pkg/reconciler/revision/revision_test.go

@@ -261,20 +261,20 @@ func (r *fixedResolver) Resolve(_ string, _ k8schain.Options, _ sets.String) (st
 }
 
 type errorResolver struct {
-	error string
+	err error
 }
 
 func (r *errorResolver) Resolve(_ string, _ k8schain.Options, _ sets.String) (string, error) {
-	return "", errors.New(r.error)
+	return "", r.err
 }
 
 func TestResolutionFailed(t *testing.T) {
 	ctx, cancel, _, controller, _ := newTestController(t)
 	defer cancel()
 
 	// Unconditionally return this error during resolution.
-	errorMessage := "I am the expected error message, hear me ROAR!"
-	controller.Reconciler.(*Reconciler).resolver = &errorResolver{errorMessage}
+	innerError := errors.New("i am the expected error message, hear me ROAR!")
+	controller.Reconciler.(*Reconciler).resolver = &errorResolver{innerError}
 
 	rev := testRevision()
 	config := testConfiguration()
@@ -295,7 +295,7 @@ func TestResolutionFailed(t *testing.T) {
 			Status: corev1.ConditionFalse,
 			Reason: "ContainerMissing",
 			Message: v1alpha1.RevisionContainerMissingMessage(
-				rev.Spec.GetContainer().Image, errorMessage),
+				rev.Spec.GetContainer().Image, "failed to resolve image to digest: "+innerError.Error()),
 			LastTransitionTime: got.LastTransitionTime,
 			Severity:           apis.ConditionSeverityError,
 		}