dotcloud/docker

package specialimage

import (
    "strings"

    "github.com/distribution/reference"
    ocispec "github.com/opencontainers/image-spec/specs-go/v1"
)

// TextPlain creates an non-container image that only contains a text/plain blob.
func TextPlain(dir string) (*ocispec.Index, error) {
    ref, err := reference.ParseNormalizedNamed("tianon/test:text-plain")
    if err != nil {
        return nil, err
    }

    emptyJsonDesc, err := writeBlob(dir, "text/plain", strings.NewReader("{}"))
    if err != nil {
        return nil, err
    }

    configDesc := emptyJsonDesc
    configDesc.MediaType = "application/vnd.oci.empty.v1+json"

    desc, err := writeJsonBlob(dir, ocispec.MediaTypeImageManifest, ocispec.Manifest{
        Config: configDesc,
        Layers: []ocispec.Descriptor{
            emptyJsonDesc,
        },
    })
    if err != nil {
        return nil, err
    }
    desc.Annotations = map[string]string{
        "io.containerd.image.name": ref.String(),
    }

    return ociImage(dir, nil, desc)
}