dockershim: support filter containers by sandbox ID

pkg/kubelet/dockershim/docker_container.go

@@ -48,7 +48,7 @@ func (ds *dockerService) ListContainers(filter *runtimeApi.ContainerFilter) ([]*
 			f.Add("status", toDockerContainerStatus(filter.GetState()))
 		}
 		if filter.PodSandboxId != nil {
-			// TODO: implement this after sandbox functions are implemented.
+			f.AddLabel(sandboxIDLabelKey, *filter.PodSandboxId)
 		}
 
 		if filter.LabelSelector != nil {
@@ -91,6 +91,8 @@ func (ds *dockerService) CreateContainer(podSandboxID string, config *runtimeApi
 	labels := makeLabels(config.GetLabels(), config.GetAnnotations())
 	// Apply a the container type label.
 	labels[containerTypeLabelKey] = containerTypeLabelContainer
+	// Write the sandbox ID in the labels.
+	labels[sandboxIDLabelKey] = podSandboxID
 
 	image := ""
 	if iSpec := config.GetImage(); iSpec != nil {

pkg/kubelet/dockershim/docker_service.go

@@ -47,8 +47,11 @@ const (
 	containerTypeLabelKey       = "io.kubernetes.docker.type"
 	containerTypeLabelSandbox   = "podsandbox"
 	containerTypeLabelContainer = "container"
+	sandboxIDLabelKey           = "io.kubernetes.sandbox.id"
 )
 
+var internalLabelKeys []string = []string{containerTypeLabelKey, sandboxIDLabelKey}
+
 func NewDockerService(client dockertools.DockerInterface) DockerLegacyService {
 	return &dockerService{
 		client: dockertools.NewInstrumentedDockerInterface(client),

pkg/kubelet/dockershim/helpers.go

@@ -84,11 +84,20 @@ func extractLabels(input map[string]string) (map[string]string, map[string]strin
 	annotations := make(map[string]string)
 	for k, v := range input {
 		// Check if the key is used internally by the shim.
-		// TODO: containerTypeLabelKey is the only internal label the shim uses
-		// right now. Expand this to a list later.
-		if k == containerTypeLabelKey {
+		internal := false
+		for _, internalKey := range internalLabelKeys {
+			// TODO: containerTypeLabelKey is the only internal label the shim uses
+			// right now. Expand this to a list later.
+			if k == internalKey {
+				internal = true
+				break
+			}
+		}
+		if internal {
 			continue
 		}
+
+		// Check if the label should be treated as an annotation.
 		if strings.HasPrefix(k, annotationPrefix) {
 			annotations[strings.TrimPrefix(k, annotationPrefix)] = v
 			continue