Initial commit

pkg/registry/image.go

@@ -0,0 +1,69 @@
+// Source: https://github.com/genuinetools/reg/blob/master/registry/image.go
+
+package registry
+
+import (
+	"fmt"
+
+	"github.com/containers/image/docker/reference"
+	digest "github.com/opencontainers/go-digest"
+)
+
+// Image holds information about an image.
+type Image struct {
+	Domain string
+	Path   string
+	Tag    string
+	Digest digest.Digest
+	named  reference.Named
+}
+
+// String returns the string representation of an image.
+func (i Image) String() string {
+	return i.named.String()
+}
+
+// Reference returns either the digest if it is non-empty or the tag for the image.
+func (i Image) Reference() string {
+	if len(i.Digest.String()) > 1 {
+		return i.Digest.String()
+	}
+
+	return i.Tag
+}
+
+// WithDigest sets the digest for an image.
+func (i *Image) WithDigest(digest digest.Digest) (err error) {
+	i.Digest = digest
+	i.named, err = reference.WithDigest(i.named, digest)
+	return err
+}
+
+// ParseImage returns an Image struct with all the values filled in for a given image.
+func ParseImage(image string) (Image, error) {
+	// Parse the image name and tag.
+	named, err := reference.ParseNormalizedNamed(image)
+	if err != nil {
+		return Image{}, fmt.Errorf("parsing image %q failed: %v", image, err)
+	}
+	// Add the latest lag if they did not provide one.
+	named = reference.TagNameOnly(named)
+
+	i := Image{
+		named:  named,
+		Domain: reference.Domain(named),
+		Path:   reference.Path(named),
+	}
+
+	// Add the tag if there was one.
+	if tagged, ok := named.(reference.Tagged); ok {
+		i.Tag = tagged.Tag()
+	}
+
+	// Add the digest if there was one.
+	if canonical, ok := named.(reference.Canonical); ok {
+		i.Digest = canonical.Digest()
+	}
+
+	return i, nil
+}