cri-o/vendor/github.com/containers/image/docker/policyconfiguration/naming.go
Andrew Pilloud de9995d5f0 dep: Update containers/image to 1d7e25b91705e4d1cddb5396baf112caeb1119f3
Signed-off-by: Andrew Pilloud <andrewpilloud@igneoussystems.com>
2017-03-13 09:33:17 -07:00

56 lines
2.2 KiB
Go

package policyconfiguration
import (
"strings"
"github.com/containers/image/docker/reference"
"github.com/pkg/errors"
)
// DockerReferenceIdentity returns a string representation of the reference, suitable for policy lookup,
// as a backend for ImageReference.PolicyConfigurationIdentity.
// The reference must satisfy !reference.IsNameOnly().
func DockerReferenceIdentity(ref reference.Named) (string, error) {
res := ref.Name()
tagged, isTagged := ref.(reference.NamedTagged)
digested, isDigested := ref.(reference.Canonical)
switch {
case isTagged && isDigested: // Note that this CAN actually happen.
return "", errors.Errorf("Unexpected Docker reference %s with both a name and a digest", reference.FamiliarString(ref))
case !isTagged && !isDigested: // This should not happen, the caller is expected to ensure !reference.IsNameOnly()
return "", errors.Errorf("Internal inconsistency: Docker reference %s with neither a tag nor a digest", reference.FamiliarString(ref))
case isTagged:
res = res + ":" + tagged.Tag()
case isDigested:
res = res + "@" + digested.Digest().String()
default: // Coverage: The above was supposed to be exhaustive.
return "", errors.New("Internal inconsistency, unexpected default branch")
}
return res, nil
}
// DockerReferenceNamespaces returns a list of other policy configuration namespaces to search,
// as a backend for ImageReference.PolicyConfigurationIdentity.
// The reference must satisfy !reference.IsNameOnly().
func DockerReferenceNamespaces(ref reference.Named) []string {
// Look for a match of the repository, and then of the possible parent
// namespaces. Note that this only happens on the expanded host names
// and repository names, i.e. "busybox" is looked up as "docker.io/library/busybox",
// then in its parent "docker.io/library"; in none of "busybox",
// un-namespaced "library" nor in "" supposedly implicitly representing "library/".
//
// ref.FullName() == ref.Hostname() + "/" + ref.RemoteName(), so the last
// iteration matches the host name (for any namespace).
res := []string{}
name := ref.Name()
for {
res = append(res, name)
lastSlash := strings.LastIndex(name, "/")
if lastSlash == -1 {
break
}
name = name[:lastSlash]
}
return res
}