Merge pull request #5958 from tonistiigi/pusher-response-error

pusher: add response details to push errors

exporter/containerimage/export.go

@@ -14,6 +14,7 @@ import (
 	"github.com/containerd/containerd/v2/core/images"
 	"github.com/containerd/containerd/v2/core/leases"
 	"github.com/containerd/containerd/v2/core/remotes/docker"
+	remoteserrors "github.com/containerd/containerd/v2/core/remotes/errors"
 	"github.com/containerd/containerd/v2/pkg/epoch"
 	"github.com/containerd/containerd/v2/pkg/labels"
 	"github.com/containerd/containerd/v2/pkg/rootfs"
@@ -355,6 +356,13 @@ func (e *imageExporterInstance) Export(ctx context.Context, src *exporter.Source
 			if e.push {
 				err = e.pushImage(ctx, src, sessionID, targetName, desc.Digest)
 				if err != nil {
+					var statusErr remoteserrors.ErrUnexpectedStatus
+					if errors.As(err, &statusErr) {
+						var dErr docker.Errors
+						if err1 := json.Unmarshal(statusErr.Body, &dErr); err1 == nil && len(dErr) > 0 {
+							err = &formattedDockerError{dErr: dErr}
+						}
+					}
 					return nil, nil, errors.Wrapf(err, "failed to push %v", targetName)
 				}
 			}
@@ -542,3 +550,36 @@ func (d *descriptorReference) Descriptor() ocispecs.Descriptor {
 func (d *descriptorReference) Release() error {
 	return d.release(context.TODO())
 }
+
+type formattedDockerError struct {
+	dErr docker.Errors
+}
+
+func (e *formattedDockerError) Error() string {
+	format := func(err error) string {
+		out := err.Error()
+		var dErr docker.Error
+		if errors.As(err, &dErr) {
+			if v, ok := dErr.Detail.(string); ok && v != "" {
+				out += " - " + v
+			}
+		}
+		return out
+	}
+	switch len(e.dErr) {
+	case 0:
+		return "<nil>"
+	case 1:
+		return format(e.dErr[0])
+	default:
+		msg := "errors:\n"
+		for _, err := range e.dErr {
+			msg += format(err) + "\n"
+		}
+		return msg
+	}
+}
+
+func (e *formattedDockerError) Unwrap() error {
+	return e.dErr
+}