dockershim: add unit tests for sandbox/container status

Also add a fake clock in the FakeDockerClient to allow testing container
CreatedAt, StartedAt, FinishedAt timestamps.

pkg/kubelet/dockertools/fake_docker_client.go

@@ -28,6 +28,7 @@ import (
 
 	dockertypes "github.com/docker/engine-api/types"
 	dockercontainer "github.com/docker/engine-api/types/container"
+	"k8s.io/kubernetes/pkg/util/clock"
 
 	"k8s.io/kubernetes/pkg/api"
 )
@@ -40,6 +41,7 @@ type calledDetail struct {
 // FakeDockerClient is a simple fake docker client, so that kubelet can be run for testing without requiring a real docker setup.
 type FakeDockerClient struct {
 	sync.Mutex
+	Clock                *clock.FakeClock
 	RunningContainerList []dockertypes.Container
 	ExitedContainerList  []dockertypes.Container
 	ContainerMap         map[string]*dockertypes.ContainerJSON
@@ -75,6 +77,7 @@ func NewFakeDockerClientWithVersion(version, apiVersion string) *FakeDockerClien
 		VersionInfo:  dockertypes.Version{Version: version, APIVersion: apiVersion},
 		Errors:       make(map[string]error),
 		ContainerMap: make(map[string]*dockertypes.ContainerJSON),
+		Clock:        clock.NewFakeClock(time.Time{}),
 	}
 }
 
@@ -292,7 +295,11 @@ func (f *FakeDockerClient) InspectContainer(id string) (*dockertypes.ContainerJS
 	if container, ok := f.ContainerMap[id]; ok {
 		return container, err
 	}
-	return nil, err
+	if err != nil {
+		// Use the custom error if it exists.
+		return nil, err
+	}
+	return nil, fmt.Errorf("container %q not found", id)
 }
 
 // InspectImage is a test-spy implementation of DockerInterface.InspectImage.
@@ -337,7 +344,8 @@ func (f *FakeDockerClient) CreateContainer(c dockertypes.ContainerCreateConfig)
 	f.RunningContainerList = append([]dockertypes.Container{
 		{ID: name, Names: []string{name}, Image: c.Config.Image, Labels: c.Config.Labels},
 	}, f.RunningContainerList...)
-	f.ContainerMap[name] = convertFakeContainer(&FakeContainer{ID: id, Name: name, Config: c.Config, HostConfig: c.HostConfig})
+	f.ContainerMap[name] = convertFakeContainer(&FakeContainer{
+		ID: id, Name: name, Config: c.Config, HostConfig: c.HostConfig, CreatedAt: f.Clock.Now()})
 	f.normalSleep(100, 25, 25)
 	return &dockertypes.ContainerCreateResponse{ID: id}, nil
 }
@@ -358,7 +366,7 @@ func (f *FakeDockerClient) StartContainer(id string) error {
 	}
 	container.State.Running = true
 	container.State.Pid = os.Getpid()
-	container.State.StartedAt = dockerTimestampToString(time.Now())
+	container.State.StartedAt = dockerTimestampToString(f.Clock.Now())
 	container.NetworkSettings.IPAddress = "2.3.4.5"
 	f.ContainerMap[id] = container
 	f.updateContainerStatus(id, statusRunningPrefix)
@@ -398,7 +406,7 @@ func (f *FakeDockerClient) StopContainer(id string, timeout int) error {
 			FinishedAt: time.Now(),
 		})
 	} else {
-		container.State.FinishedAt = dockerTimestampToString(time.Now())
+		container.State.FinishedAt = dockerTimestampToString(f.Clock.Now())
 		container.State.Running = false
 	}
 	f.ContainerMap[id] = container