// Creates a name which can be reversed to identify both full pod name and container name.
// This function returns stable name, unique name and a unique id.
// Although rand.Uint32() is not really unique, but it's enough for us because error will
// only occur when instances of the same container in the same pod have the same UID. The
// chance is really slim.
func BuildDockerName(dockerName KubeletContainerName, container *v1.Container) (string, string, string) {
containerName := dockerName.ContainerName + "." + strconv.FormatUint(kubecontainer.HashContainerLegacy(container), 16)
stableName := fmt.Sprintf("%s_%s_%s_%s",
containerNamePrefix,
containerName,
dockerName.PodFullName,
dockerName.PodUID)
UID := fmt.Sprintf("%08x", rand.Uint32())
return stableName, fmt.Sprintf("%s_%s", stableName, UID), UID
}
// Unpacks a container name, returning the pod full name and container name we would have used to
// construct the docker name. If we are unable to parse the name, an error is returned.
func ParseDockerName(name string) (dockerName *KubeletContainerName, hash uint64, err error) {
// For some reason docker appears to be appending '/' to names.
// If it's there, strip it.
name = strings.TrimPrefix(name, "/")
parts := strings.Split(name, "_")
if len(parts) == 0 || parts[0] != containerNamePrefix {
err = fmt.Errorf("failed to parse Docker container name %q into parts", name)
return nil, 0, err
}
if len(parts) < 6 {
// We have at least 5 fields. We may have more in the future.
// Anything with less fields than this is not something we can
// manage.
glog.Warningf("found a container with the %q prefix, but too few fields (%d): %q", containerNamePrefix, len(parts), name)
err = fmt.Errorf("Docker container name %q has less parts than expected %v", name, parts)
return nil, 0, err
}
nameParts := strings.Split(parts[1], ".")
containerName := nameParts[0]
if len(nameParts) > 1 {
hash, err = strconv.ParseUint(nameParts[1], 16, 32)
if err != nil {
glog.Warningf("invalid container hash %q in container %q", nameParts[1], name)
}
}
podFullName := parts[2] + "_" + parts[3]
podUID := types.UID(parts[4])
return &KubeletContainerName{podFullName, podUID, containerName}, hash, nil
}
