added a oci function to support generic image (#48)

go.mod

@@ -13,5 +13,9 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/opencontainers/image-spec v1.1.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/sync v0.6.0 // indirect
+	oras.land/oras-go/v2 v2.5.0 // indirect
 )

go.sum

@@ -2,13 +2,21 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
 github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
+github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
+github.com/opencontainers/image-spec v1.1.0 h1:8SG7/vwALn54lVB/0yZ/MMwhFrPYtpEHQb2IpWsCzug=
+github.com/opencontainers/image-spec v1.1.0/go.mod h1:W4s4sFTMaBeK1BQLXbG4AdM2szdn85PY75RI83NrTrM=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/santhosh-tekuri/jsonschema/v5 v5.3.1 h1:lZUw3E0/J3roVtGQ+SCrUrg3ON6NgVqpn3+iol9aGu4=
 github.com/santhosh-tekuri/jsonschema/v5 v5.3.1/go.mod h1:uToXkOrWAZ6/Oc07xWQrPOhJotwFIyu2bBVN41fcDUY=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
+golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+oras.land/oras-go/v2 v2.5.0 h1:o8Me9kLY74Vp5uw07QXPiitjsw7qNXi8Twd+19Zf02c=
+oras.land/oras-go/v2 v2.5.0/go.mod h1:z4eisnLP530vwIOUOJeBIj0aGI0L1C3d53atvCBqZHg=

uriget/example_test.go

@@ -51,3 +51,38 @@ func ExampleWithHttpClient() {
 	fmt.Println(err)
 	// Output: failed to make get request: Get "https://example.com": no proxy
 }
+func ExampleGetFile_oci() {
+	testUrl := "oci://ghcr.io/score-spec/score-compose:0.18.0"
+	buff, err := GetFile(context.Background(), testUrl)
+	if err != nil {
+		fmt.Println("failed to pull OCI image:", err)
+		return
+	}
+	fmt.Println(len(buff) > 0)
+	// Output:
+	// true
+}
+
+func ExampleGetFile_ociNoTag() {
+	testUrl := "oci://ghcr.io/score-spec/score-compose"
+	buff, err := GetFile(context.Background(), testUrl)
+	if err != nil {
+		fmt.Println("failed to pull OCI image:", err)
+		return
+	}
+	fmt.Println(len(buff) > 0)
+	// Output:
+	// true
+}
+
+func ExampleGetFile_ociWithDigest() {
+	testUrl := "oci://ghcr.io/score-spec/score-compose@sha256:f3d8d5485a751cbdc91e073df1b6fbcde83f85a86ee3bc7d53e05b00452baedd"
+	buff, err := GetFile(context.Background(), testUrl)
+	if err != nil {
+		fmt.Println("failed to pull OCI image:", err)
+		return
+	}
+	fmt.Println(len(buff) > 0)
+	// Output:
+	// true
+}

uriget/uriget.go

@@ -16,6 +16,11 @@ import (
 	"path/filepath"
 	"strings"
 	"time"
+
+	"oras.land/oras-go/v2"
+	"oras.land/oras-go/v2/content/oci"
+	"oras.land/oras-go/v2/registry"
+	"oras.land/oras-go/v2/registry/remote"
 )
 
 // options is a struct holding fields that may need to have overrides in certain environments or during unit testing.
@@ -110,6 +115,8 @@ func GetFile(ctx context.Context, rawUri string, optionFuncs ...Option) ([]byte,
 		fallthrough
 	case "git-https":
 		return opts.getGit(ctx, u)
+	case "oci":
+		return opts.getOci(ctx, u)
 	default:
 		return nil, fmt.Errorf("unsupported scheme '%s'", u.Scheme)
 	}
@@ -233,3 +240,29 @@ func (o *options) getGit(ctx context.Context, u *url.URL) ([]byte, error) {
 	o.logger.Printf("Read %d bytes from %s", len(buff), filepath.Join(td, subPath))
 	return buff, nil
 }
+
+func (o *options) getOci(ctx context.Context, u *url.URL) ([]byte, error) {
+	ref, err := registry.ParseReference(u.Host + u.Path)
+	if err != nil {
+		return nil, fmt.Errorf("can't parse artifact URL into a valid reference: %w", err)
+	}
+	store, err := oci.New(o.tempDir)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create OCI layout store: %w", err)
+	}
+	remoteRepo, err := remote.NewRepository(ref.String())
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to remote repository: %w", err)
+	}
+	tag := "latest"
+	if ref.Reference != "" {
+		tag = ref.Reference
+	}
+	manifestDescriptor, err := oras.Copy(ctx, remoteRepo, tag, store, tag, oras.DefaultCopyOptions)
+	if err != nil {
+		return nil, fmt.Errorf("failed to pull OCI image: %w", err)
+	}
+
+	o.logger.Printf("Pulled OCI image: %s with manifest descriptor: %v", u.String(), manifestDescriptor.Digest)
+	return []byte(manifestDescriptor.Digest), nil
+}