feat: Support OCI values

Signed-off-by: George Jenkins <gvjenkins@gmail.com>

README.md

@@ -6,6 +6,30 @@
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/3131/badge)](https://bestpractices.coreinfrastructure.org/projects/3131)
 [![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/helm/helm/badge)](https://scorecard.dev/viewer/?uri=github.com/helm/helm)
 
+## PR
+
+Run a registry:
+```
+docker run -d -p 5000:5000 --restart always --name registry docker.io/registry:3.0.0-rc.2
+```
+
+Create a chart and values, push values to registry:
+```
+helm create oci-values-demo
+$ cat value-overides.yaml
+---
+replicaCount: 3
+$ oras push localhost:5000/oci-values-demo-values:demo value-overides.yaml:application/vnd.cncf.helm.values.v1
+```
+
+Install the chart, pulling values from OCI:
+```
+make && ./bin/helm upgrade --install oci-values-demo-release oci-values-demo/ -f oci://localhost:5000/oci-values-demo-values:demo
+```
+
+
+
+
 Helm is a tool for managing Charts. Charts are packages of pre-configured Kubernetes resources.
 
 Use Helm to:

pkg/cli/values/options.go

@@ -131,7 +131,8 @@ func readFile(filePath string, p getter.Providers) ([]byte, error) {
 	if err != nil {
 		return os.ReadFile(filePath)
 	}
-	data, err := g.Get(filePath, getter.WithURL(filePath))
+
+	data, err := g.Get(filePath, getter.WithURL(filePath), getter.WithTarget("values"))
 	if err != nil {
 		return nil, err
 	}

pkg/getter/getter.go

@@ -47,6 +47,7 @@ type options struct {
 	registryClient        *registry.Client
 	timeout               time.Duration
 	transport             *http.Transport
+	target                string
 }
 
 // Option allows specifying various settings configurable by the user for overriding the defaults
@@ -143,6 +144,13 @@ func WithTransport(transport *http.Transport) Option {
 	}
 }
 
+// WithTransport sets the http.Transport to allow overwriting the HTTPGetter default.
+func WithTarget(target string) Option {
+	return func(opts *options) {
+		opts.target = target
+	}
+}
+
 // Getter is an interface to support GET to the specified URL.
 type Getter interface {
 	// Get file content by url string

pkg/getter/ocigetter.go

@@ -39,6 +39,7 @@ type OCIGetter struct {
 
 // Get performs a Get from repo.Getter and returns the body.
 func (g *OCIGetter) Get(href string, options ...Option) (*bytes.Buffer, error) {
+	g.opts.target = "chart"
 	for _, opt := range options {
 		opt(&g.opts)
 	}
@@ -76,12 +77,19 @@ func (g *OCIGetter) get(href string) (*bytes.Buffer, error) {
 		return nil, err
 	}
 
+	switch g.opts.target {
+	case "values":
+		return bytes.NewBuffer(result.Values.Data), nil
+	case "chart":
 		if requestingProv {
 			return bytes.NewBuffer(result.Prov.Data), nil
 		}
 		return bytes.NewBuffer(result.Chart.Data), nil
 	}
 
+	return nil, fmt.Errorf("unknown get target: %s", g.opts.target)
+}
+
 // NewOCIGetter constructs a valid http/https client as a Getter
 func NewOCIGetter(ops ...Option) (Getter, error) {
 	var client OCIGetter

pkg/registry/client.go

@@ -399,6 +399,7 @@ type (
 		Chart    *DescriptorPullSummaryWithMeta `json:"chart"`
 		Prov     *DescriptorPullSummary         `json:"prov"`
 		Ref      string                         `json:"ref"`
+		Values   *DescriptorPullSummary         `json:"values"`
 	}
 
 	DescriptorPullSummary struct {
@@ -436,24 +437,23 @@ func (c *Client) Pull(ref string, options ...PullOption) (*PullResult, error) {
 		return nil, errors.New(
 			"must specify at least one layer to pull (chart/prov)")
 	}
-	memoryStore := memory.New()
-	allowedMediaTypes := []string{
-		ocispec.MediaTypeImageManifest,
-		ConfigMediaType,
-	}
-	minNumDescriptors := 1 // 1 for the config
-	if operation.withChart {
-		minNumDescriptors++
-		allowedMediaTypes = append(allowedMediaTypes, ChartLayerMediaType, LegacyChartLayerMediaType)
-	}
-	if operation.withProv {
-		if !operation.ignoreMissingProv {
-			minNumDescriptors++
-		}
-		allowedMediaTypes = append(allowedMediaTypes, ProvLayerMediaType)
-	}
 
-	var descriptors, layers []ocispec.Descriptor
+	memoryStore := memory.New()
+	//allowedMediaTypes := []string{
+	//	ocispec.MediaTypeImageManifest,
+	//	ConfigMediaType,
+	//}
+	//minNumDescriptors := 1 // 1 for the config
+	//if operation.withChart {
+	//	minNumDescriptors++
+	//	allowedMediaTypes = append(allowedMediaTypes, ChartLayerMediaType, LegacyChartLayerMediaType)
+	//}
+	//if operation.withProv {
+	//	if !operation.ignoreMissingProv {
+	//		minNumDescriptors++
+	//	}
+	//	allowedMediaTypes = append(allowedMediaTypes, ProvLayerMediaType)
+	//}
 
 	repository, err := remote.NewRepository(parsedRef.String())
 	if err != nil {
@@ -464,16 +464,17 @@ func (c *Client) Pull(ref string, options ...PullOption) (*PullResult, error) {
 
 	ctx := context.Background()
 
-	sort.Strings(allowedMediaTypes)
+	//sort.Strings(allowedMediaTypes)
 
 	var mu sync.Mutex
+	var layers []ocispec.Descriptor
 	manifest, err := oras.Copy(ctx, repository, parsedRef.String(), memoryStore, "", oras.CopyOptions{
 		CopyGraphOptions: oras.CopyGraphOptions{
 			PreCopy: func(_ context.Context, desc ocispec.Descriptor) error {
-				mediaType := desc.MediaType
+				//mediaType := desc.MediaType
-				if i := sort.SearchStrings(allowedMediaTypes, mediaType); i >= len(allowedMediaTypes) || allowedMediaTypes[i] != mediaType {
+				//if i := sort.SearchStrings(allowedMediaTypes, mediaType); i >= len(allowedMediaTypes) || allowedMediaTypes[i] != mediaType {
-					return errors.Errorf("media type %q is not allowed, found in descriptor with digest: %q", mediaType, desc.Digest)
+				//	return errors.Errorf("media type %q is not allowed, found in descriptor with digest: %q", mediaType, desc.Digest)
-				}
+				//}
 
 				mu.Lock()
 				layers = append(layers, desc)
@@ -486,17 +487,19 @@ func (c *Client) Pull(ref string, options ...PullOption) (*PullResult, error) {
 		return nil, err
 	}
 
+	var descriptors []ocispec.Descriptor
 	descriptors = append(descriptors, manifest)
 	descriptors = append(descriptors, layers...)
 
-	numDescriptors := len(descriptors)
+	if manifest.MediaType != "application/vnd.oci.image.manifest.v1+json" {
-	if numDescriptors < minNumDescriptors {
+		return nil, fmt.Errorf("unexpected reference mediatype: %s", manifest.MediaType)
-		return nil, fmt.Errorf("manifest does not contain minimum number of descriptors (%d), descriptors found: %d",
-			minNumDescriptors, numDescriptors)
 	}
+
 	var configDescriptor *ocispec.Descriptor
 	var chartDescriptor *ocispec.Descriptor
 	var provDescriptor *ocispec.Descriptor
+	var valuesDescriptor *ocispec.Descriptor
+
 	for _, descriptor := range descriptors {
 		d := descriptor
 		switch d.MediaType {
@@ -506,11 +509,30 @@ func (c *Client) Pull(ref string, options ...PullOption) (*PullResult, error) {
 			chartDescriptor = &d
 		case ProvLayerMediaType:
 			provDescriptor = &d
+		case ValuesMediaType:
+			valuesDescriptor = &d
 		case LegacyChartLayerMediaType:
 			chartDescriptor = &d
 			fmt.Fprintf(c.out, "Warning: chart media type %s is deprecated\n", LegacyChartLayerMediaType)
 		}
 	}
+
+	if valuesDescriptor != nil {
+		data, err := content.FetchAll(ctx, memoryStore, *valuesDescriptor)
+		if err != nil {
+			return nil, fmt.Errorf("unable to retrieve blob with digest %s: %w", valuesDescriptor.Digest, err)
+		}
+
+		return &PullResult{
+			Ref: parsedRef.String(),
+			Values: &DescriptorPullSummary{
+				Digest: valuesDescriptor.Digest.String(),
+				Size:   valuesDescriptor.Size,
+				Data:   data,
+			},
+		}, nil
+	}
+
 	if configDescriptor == nil {
 		return nil, fmt.Errorf("could not load config with mediatype %s", ConfigMediaType)
 	}
@@ -539,6 +561,7 @@ func (c *Client) Pull(ref string, options ...PullOption) (*PullResult, error) {
 		Chart:  &DescriptorPullSummaryWithMeta{},
 		Prov:   &DescriptorPullSummary{},
 		Ref:    parsedRef.String(),
+		Values: nil,
 	}
 
 	result.Manifest.Data, err = content.FetchAll(ctx, memoryStore, manifest)

pkg/registry/constants.go

@@ -32,6 +32,9 @@ const (
 	// ProvLayerMediaType is the reserved media type for Helm chart provenance files
 	ProvLayerMediaType = "application/vnd.cncf.helm.chart.provenance.v1.prov"
 
+	// ValuesMediaType is the reserved media type for the Helm chart values
+	ValuesMediaType = "application/vnd.cncf.helm.values.v1"
+
 	// LegacyChartLayerMediaType is the legacy reserved media type for Helm chart package content.
 	LegacyChartLayerMediaType = "application/tar+gzip"
 )