Method manifestDigest

docker/docker_image_src.go:490–504

manifestDigest returns a digest of the manifest, from instanceDigest if non-nil; or from the supplied reference, or finally, from a fetched manifest.

(ctx context.Context, instanceDigest *digest.Digest)

// manifestDigest returns a digest of the manifest, from instanceDigest if non-nil; or from the supplied reference,
// or finally, from a fetched manifest.
func (s *dockerImageSource) manifestDigest(ctx context.Context, instanceDigest *digest.Digest) (digest.Digest, error) {
	if instanceDigest != nil {
		return *instanceDigest, nil
	}
	if digested, ok := s.physicalRef.ref.(reference.Digested); ok {
		d := digested.Digest()
		if d.Algorithm() == digest.Canonical {
			return d, nil
		}
	}
	if err := s.ensureManifestIsLoaded(ctx); err != nil {
		return "", err
	}
	return manifest.Digest(s.cachedManifest)
}

// appendSignaturesFromLookaside implements GetSignaturesWithFormat() from the lookaside location configured in s.c.signatureBase,
// which is not nil, storing the signatures to *dest.