distribution: use ad-hoc trustkey for tests

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

distribution/push_v2.go

@@ -24,6 +24,7 @@ import (
 	"github.com/docker/docker/pkg/progress"
 	"github.com/docker/docker/pkg/stringid"
 	"github.com/docker/docker/registry"
+	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -187,7 +188,7 @@ func (p *pusher) pushTag(ctx context.Context, ref reference.NamedTagged, id dige
 
 	putOptions := []distribution.ManifestServiceOption{distribution.WithTag(ref.Tag())}
 	if _, err = manSvc.Put(ctx, manifest, putOptions...); err != nil {
-		if runtime.GOOS == "windows" || p.config.TrustKey == nil || p.config.RequireSchema2 {
+		if runtime.GOOS == "windows" || p.config.RequireSchema2 {
 			logrus.Warnf("failed to upload schema2 manifest: %v", err)
 			return err
 		}
@@ -211,7 +212,11 @@ func (p *pusher) pushTag(ctx context.Context, ref reference.NamedTagged, id dige
 		if err != nil {
 			return err
 		}
-		builder = schema1.NewConfigManifestBuilder(p.repo.Blobs(ctx), p.config.TrustKey, manifestRef, imgConfig)
+		pk, err := libtrust.GenerateECP256PrivateKey()
+		if err != nil {
+			return errors.Wrap(err, "unexpected error generating private key")
+		}
+		builder = schema1.NewConfigManifestBuilder(p.repo.Blobs(ctx), pk, manifestRef, imgConfig)
 		manifest, err = manifestFromBuilder(ctx, builder, descriptors)
 		if err != nil {
 			return err