Return more detailed errors when fixup fails (#113)

* Return more detailed errors when fixup fails

It's not possible from the current error to tell what went wrong since
the real error is only sent to the debug logger, and isn't included in
the returned error message.

I have updated the errors returned from each fixup function so that you
can tell where the fixup failed from the error message.

Signed-off-by: Carolyn Van Slyck <me@carolynvanslyck.com>

* Don't fail immediatley if a fixup fails

When applying fixups to an image, accumulate any errors and only return an error if
the image ultimately was unable to be pushed.

Signed-off-by: Carolyn Van Slyck <me@carolynvanslyck.com>

remotes/fixup.go

@@ -13,6 +13,7 @@ import (
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/remotes"
 	"github.com/docker/distribution/reference"
+	"github.com/hashicorp/go-multierror"
 	ocischemav1 "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
@@ -216,63 +217,75 @@ func fixupBaseImage(ctx context.Context, name string, baseImage *bundle.BaseImag
 		pushLocalImage,
 	}
 
+	var bigErr *multierror.Error
 	for _, f := range fixups {
 		info, pushed, ok, err := f(ctx, targetRepoOnly, baseImage, cfg)
 		if err != nil {
 			log.G(ctx).Debug(err)
+			// do not stop trying fixups after the first error. Only report the errors if all fixups were unable to push the image.
+			bigErr = multierror.Append(bigErr, fmt.Errorf("failed to fixup the image %s for service %q: %v", baseImage.Image, name, err))
 		}
 		if ok {
 			return info, pushed, nil
 		}
 	}
 
-	return imageFixupInfo{}, false, fmt.Errorf("failed to resolve or push image for service %q", name)
+	return imageFixupInfo{}, false, bigErr.ErrorOrNil()
 }
 
 func pushByDigest(ctx context.Context, target reference.Named, baseImage *bundle.BaseImage, cfg fixupConfig) (imageFixupInfo, bool, bool, error) {
 	if baseImage.Image != "" || !cfg.pushImages {
 		return imageFixupInfo{}, false, false, nil
 	}
 	descriptor, err := pushImageToTarget(ctx, baseImage.Digest, cfg)
+	if err != nil {
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to push digested image %s@%s to target %s: %v", baseImage.Image, baseImage.Digest, target, err)
+	}
 	return imageFixupInfo{
 		targetRepo:         target,
 		sourceRef:          nil,
 		resolvedDescriptor: descriptor,
-	}, true, err == nil, err
+	}, true, true, nil
 }
 
 func resolveImage(ctx context.Context, target reference.Named, baseImage *bundle.BaseImage, cfg fixupConfig) (imageFixupInfo, bool, bool, error) {
 	sourceImageRef, err := ref(baseImage.Image)
 	if err != nil {
-		return imageFixupInfo{}, false, false, err
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to resolve image: invalid source ref %s: %v", baseImage.Image, err)
 	}
 	_, descriptor, err := cfg.resolver.Resolve(ctx, sourceImageRef.String())
+	if err != nil {
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to resolve image %s: %v", sourceImageRef.String(), err)
+	}
 	return imageFixupInfo{
 		targetRepo:         target,
 		sourceRef:          sourceImageRef,
 		resolvedDescriptor: descriptor,
-	}, false, err == nil, err
+	}, false, true, nil
 }
 
 func resolveImageInRelocationMap(ctx context.Context, target reference.Named, baseImage *bundle.BaseImage, cfg fixupConfig) (imageFixupInfo, bool, bool, error) {
 	sourceImageRef, err := ref(baseImage.Image)
 	if err != nil {
-		return imageFixupInfo{}, false, false, err
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to resolve image in relocation map: invalid source ref %s: %v", baseImage.Image, err)
 	}
 	relocatedRef, ok := cfg.relocationMap[baseImage.Image]
 	if !ok {
 		return imageFixupInfo{}, false, false, nil
 	}
 	relocatedImageRef, err := ref(relocatedRef)
 	if err != nil {
-		return imageFixupInfo{}, false, false, err
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to resolve image in relocation map: invalid target ref %s: %v", relocatedRef, err)
 	}
 	_, descriptor, err := cfg.resolver.Resolve(ctx, relocatedImageRef.String())
+	if err != nil {
+		return imageFixupInfo{}, false, false, err
+	}
 	return imageFixupInfo{
 		targetRepo:         target,
 		sourceRef:          sourceImageRef,
 		resolvedDescriptor: descriptor,
-	}, false, err == nil, err
+	}, false, true, nil
 }
 
 func pushLocalImage(ctx context.Context, target reference.Named, baseImage *bundle.BaseImage, cfg fixupConfig) (imageFixupInfo, bool, bool, error) {
@@ -281,14 +294,17 @@ func pushLocalImage(ctx context.Context, target reference.Named, baseImage *bund
 	}
 	sourceImageRef, err := ref(baseImage.Image)
 	if err != nil {
-		return imageFixupInfo{}, false, false, err
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to push local image: invalid source ref %s: %v", baseImage.Image, err)
 	}
 	descriptor, err := pushImageToTarget(ctx, baseImage.Image, cfg)
+	if err != nil {
+		return imageFixupInfo{}, false, false, fmt.Errorf("failed to push local image %s: %v", baseImage.Image, err)
+	}
 	return imageFixupInfo{
 		targetRepo:         target,
 		sourceRef:          sourceImageRef,
 		resolvedDescriptor: descriptor,
-	}, true, err == nil, err
+	}, true, true, nil
 }
 
 func ref(str string) (reference.Named, error) {