build: fail early if trying to export index annotations with moby exporter

bake/bake.go

@@ -1544,12 +1544,12 @@ func toBuildOpt(t *Target, inp *Input) (*build.Options, error) {
 		return nil, err
 	}
 
-	annotations, err := buildflags.ParseAnnotations(t.Annotations)
+	bo.Annotations, err = buildflags.ParseAnnotations(t.Annotations)
 	if err != nil {
 		return nil, err
 	}
 	for _, e := range bo.Exports {
-		for k, v := range annotations {
+		for k, v := range bo.Annotations {
 			e.Attrs[k.String()] = v
 		}
 	}

build/build.go

@@ -93,6 +93,7 @@ type Options struct {
 	ProvenanceResponseMode confutil.MetadataProvenanceMode
 	SourcePolicy           *spb.Policy
 	GroupRef               string
+	Annotations            map[exptypes.AnnotationKey]string // Not used during build, annotations are already set in Exports. Just used to check for support with drivers.
 }
 
 type CallFunc struct {

build/opt.go

@@ -28,6 +28,7 @@ import (
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/client/ociindex"
+	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	gateway "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/identity"
 	"github.com/moby/buildkit/session"
@@ -180,6 +181,20 @@ func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt *O
 		}
 	}
 
+	// check if index annotations are supported by docker driver
+	if len(opt.Exports) > 0 && opt.CallFunc == nil && len(opt.Annotations) > 0 && nodeDriver.IsMobyDriver() && !nodeDriver.Features(ctx)[driver.MultiPlatform] {
+		for _, exp := range opt.Exports {
+			if exp.Type == "image" || exp.Type == "docker" {
+				for ak := range opt.Annotations {
+					switch ak.Type {
+					case exptypes.AnnotationIndex, exptypes.AnnotationIndexDescriptor:
+						return nil, nil, errors.New("index annotations not supported for single platform export")
+					}
+				}
+			}
+		}
+	}
+
 	// fill in image exporter names from tags
 	if len(opt.Tags) > 0 {
 		tags := make([]string, len(opt.Tags))

commands/build.go

@@ -1062,13 +1062,13 @@ func RunBuild(ctx context.Context, dockerCli command.Cli, in *BuildOptions, inSt
 		}
 	}
 
-	annotations, err := buildflags.ParseAnnotations(in.Annotations)
+	opts.Annotations, err = buildflags.ParseAnnotations(in.Annotations)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "parse annotations")
 	}
 
 	for _, o := range outputs {
-		for k, v := range annotations {
+		for k, v := range opts.Annotations {
 			o.Attrs[k.String()] = v
 		}
 	}

tests/build.go

@@ -78,6 +78,7 @@ var buildTests = []func(t *testing.T, sb integration.Sandbox){
 	testBuildCall,
 	testBuildCheckCallOutput,
 	testBuildExtraHosts,
+	testBuildIndexAnnotationsLoadDocker,
 }
 
 func testBuild(t *testing.T, sb integration.Sandbox) {
@@ -1341,6 +1342,17 @@ RUN cat /etc/hosts | grep myhostmulti | grep 162.242.195.82
 	require.NoError(t, err, string(out))
 }
 
+func testBuildIndexAnnotationsLoadDocker(t *testing.T, sb integration.Sandbox) {
+	if sb.DockerAddress() == "" {
+		t.Skip("only testing with docker available")
+	}
+	skipNoCompatBuildKit(t, sb, ">= 0.11.0-0", "annotations")
+	dir := createTestProject(t)
+	out, err := buildCmd(sb, withArgs("--annotation", "index:foo=bar", "--provenance", "false", "--output", "type=docker", dir))
+	require.Error(t, err, out)
+	require.Contains(t, out, "index annotations not supported for single platform export")
+}
+
 func createTestProject(t *testing.T) string {
 	dockerfile := []byte(`
 FROM busybox:latest AS base