cloudfoundry-incubator/eirini

package docker

import (
    "context"

    "github.com/containers/image/docker"
    "github.com/containers/image/image"
    "github.com/containers/image/types"
    v1 "github.com/opencontainers/image-spec/specs-go/v1"
    "github.com/pkg/errors"
)

func Fetch(dockerRef string, sysCtx types.SystemContext) (*v1.ImageConfig, error) {
    ref, err := docker.ParseReference(dockerRef)
    if err != nil {
        return nil, errors.Wrap(err, "failed to parse docker reference")
    }

    ctx := context.Background()

    imgSrc, err := ref.NewImageSource(ctx, &sysCtx)
    if err != nil {
        return nil, errors.Wrap(err, "failed to get image source")
    }
    defer imgSrc.Close()

    img, err := image.FromUnparsedImage(ctx, &sysCtx, image.UnparsedInstance(imgSrc, nil))
    if err != nil {
        return nil, errors.Wrap(err, "failed to get image")
    }

    imgV1, err := img.OCIConfig(ctx)
    if err != nil {
        return nil, errors.Wrap(err, "failed to get oci config")
    }

    return &imgV1.Config, nil
}