Use runtime instread of dockerclient in container gc

pkg/kubelet/container/runtime.go

@@ -22,6 +22,7 @@ import (
 	"io"
 	"reflect"
 	"strings"
+	"time"
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
@@ -74,6 +75,8 @@ type Runtime interface {
 	// specifies whether the runtime returns all containers including those already
 	// exited and dead containers (used for garbage collection).
 	GetPods(all bool) ([]*Pod, error)
+	// Garbage collection of dead containers
+	GarbageCollect(maxPerPodContainer, maxContainers int, minAge time.Duration) error
 	// Syncs the running pod into the desired pod.
 	SyncPod(pod *api.Pod, runningPod Pod, podStatus api.PodStatus, pullSecrets []api.Secret, backOff *util.Backoff) error
 	// KillPod kills all the containers of a pod. Pod may be nil, running pod must not be.

pkg/kubelet/container_gc.go

@@ -18,16 +18,9 @@ package kubelet
 
 import (
 	"fmt"
-	"os"
-	"path"
-	"path/filepath"
-	"sort"
 	"time"
 
-	docker "github.com/fsouza/go-dockerclient"
-	"github.com/golang/glog"
-	"k8s.io/kubernetes/pkg/kubelet/dockertools"
-	"k8s.io/kubernetes/pkg/types"
+	"k8s.io/kubernetes/pkg/kubelet/container"
 )
 
 // Specified a policy for garbage collecting containers.
@@ -53,217 +46,25 @@ type containerGC interface {
 
 // TODO(vmarmol): Preferentially remove pod infra containers.
 type realContainerGC struct {
-	// Docker client to use.
-	dockerClient dockertools.DockerInterface
+	// Container runtime
+	runtime container.Runtime
 
 	// Policy for garbage collection.
 	policy ContainerGCPolicy
-
-	// The path to the symlinked docker logs
-	containerLogsDir string
 }
 
 // New containerGC instance with the specified policy.
-func newContainerGC(dockerClient dockertools.DockerInterface, policy ContainerGCPolicy) (containerGC, error) {
+func newContainerGC(runtime container.Runtime, policy ContainerGCPolicy) (containerGC, error) {
 	if policy.MinAge < 0 {
 		return nil, fmt.Errorf("invalid minimum garbage collection age: %v", policy.MinAge)
 	}
 
 	return &realContainerGC{
-		dockerClient:     dockerClient,
-		policy:           policy,
-		containerLogsDir: containerLogsDir,
+		runtime: runtime,
+		policy:  policy,
 	}, nil
 }
 
-// Internal information kept for containers being considered for GC.
-type containerGCInfo struct {
-	// Docker ID of the container.
-	id string
-
-	// Docker name of the container.
-	name string
-
-	// Creation time for the container.
-	createTime time.Time
-
-	// Full pod name, including namespace in the format `namespace_podName`.
-	// This comes from dockertools.ParseDockerName(...)
-	podNameWithNamespace string
-
-	// Container name in pod
-	containerName string
-}
-
-// Containers are considered for eviction as units of (UID, container name) pair.
-type evictUnit struct {
-	// UID of the pod.
-	uid types.UID
-
-	// Name of the container in the pod.
-	name string
-}
-
-type containersByEvictUnit map[evictUnit][]containerGCInfo
-
-// Returns the number of containers in this map.
-func (cu containersByEvictUnit) NumContainers() int {
-	num := 0
-	for key := range cu {
-		num += len(cu[key])
-	}
-
-	return num
-}
-
-// Returns the number of pod in this map.
-func (cu containersByEvictUnit) NumEvictUnits() int {
-	return len(cu)
-}
-
-// Newest first.
-type byCreated []containerGCInfo
-
-func (a byCreated) Len() int           { return len(a) }
-func (a byCreated) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-func (a byCreated) Less(i, j int) bool { return a[i].createTime.After(a[j].createTime) }
-
 func (cgc *realContainerGC) GarbageCollect() error {
-	// Separate containers by evict units.
-	evictUnits, unidentifiedContainers, err := cgc.evictableContainers()
-	if err != nil {
-		return err
-	}
-
-	// Remove unidentified containers.
-	for _, container := range unidentifiedContainers {
-		glog.Infof("Removing unidentified dead container %q with ID %q", container.name, container.id)
-		err = cgc.dockerClient.RemoveContainer(docker.RemoveContainerOptions{ID: container.id, RemoveVolumes: true})
-		if err != nil {
-			glog.Warningf("Failed to remove unidentified dead container %q: %v", container.name, err)
-		}
-	}
-
-	// Enforce max containers per evict unit.
-	if cgc.policy.MaxPerPodContainer >= 0 {
-		cgc.enforceMaxContainersPerEvictUnit(evictUnits, cgc.policy.MaxPerPodContainer)
-	}
-
-	// Enforce max total number of containers.
-	if cgc.policy.MaxContainers >= 0 && evictUnits.NumContainers() > cgc.policy.MaxContainers {
-		// Leave an equal number of containers per evict unit (min: 1).
-		numContainersPerEvictUnit := cgc.policy.MaxContainers / evictUnits.NumEvictUnits()
-		if numContainersPerEvictUnit < 1 {
-			numContainersPerEvictUnit = 1
-		}
-		cgc.enforceMaxContainersPerEvictUnit(evictUnits, numContainersPerEvictUnit)
-
-		// If we still need to evict, evict oldest first.
-		numContainers := evictUnits.NumContainers()
-		if numContainers > cgc.policy.MaxContainers {
-			flattened := make([]containerGCInfo, 0, numContainers)
-			for uid := range evictUnits {
-				flattened = append(flattened, evictUnits[uid]...)
-			}
-			sort.Sort(byCreated(flattened))
-
-			cgc.removeOldestN(flattened, numContainers-cgc.policy.MaxContainers)
-		}
-	}
-
-	// Remove dead symlinks - should only happen on upgrade
-	// from a k8s version without proper log symlink cleanup
-	logSymlinks, _ := filepath.Glob(path.Join(cgc.containerLogsDir, fmt.Sprintf("*.%s", dockertools.LogSuffix)))
-	for _, logSymlink := range logSymlinks {
-		if _, err = os.Stat(logSymlink); os.IsNotExist(err) {
-			err = os.Remove(logSymlink)
-			if err != nil {
-				glog.Warningf("Failed to remove container log dead symlink %q: %v", logSymlink, err)
-			}
-		}
-	}
-
-	return nil
-}
-
-func (cgc *realContainerGC) enforceMaxContainersPerEvictUnit(evictUnits containersByEvictUnit, MaxContainers int) {
-	for uid := range evictUnits {
-		toRemove := len(evictUnits[uid]) - MaxContainers
-
-		if toRemove > 0 {
-			evictUnits[uid] = cgc.removeOldestN(evictUnits[uid], toRemove)
-		}
-	}
-}
-
-// Removes the oldest toRemove containers and returns the resulting slice.
-func (cgc *realContainerGC) removeOldestN(containers []containerGCInfo, toRemove int) []containerGCInfo {
-	// Remove from oldest to newest (last to first).
-	numToKeep := len(containers) - toRemove
-	for i := numToKeep; i < len(containers); i++ {
-		err := cgc.dockerClient.RemoveContainer(docker.RemoveContainerOptions{ID: containers[i].id, RemoveVolumes: true})
-		if err != nil {
-			glog.Warningf("Failed to remove dead container %q: %v", containers[i].name, err)
-		}
-		symlinkPath := dockertools.LogSymlink(cgc.containerLogsDir, containers[i].podNameWithNamespace, containers[i].containerName, containers[i].id)
-		err = os.Remove(symlinkPath)
-		if err != nil && !os.IsNotExist(err) {
-			glog.Warningf("Failed to remove container %q log symlink %q: %v", containers[i].name, symlinkPath, err)
-		}
-	}
-
-	// Assume we removed the containers so that we're not too aggressive.
-	return containers[:numToKeep]
-}
-
-// Get all containers that are evictable. Evictable containers are: not running
-// and created more than MinAge ago.
-func (cgc *realContainerGC) evictableContainers() (containersByEvictUnit, []containerGCInfo, error) {
-	containers, err := dockertools.GetKubeletDockerContainers(cgc.dockerClient, true)
-	if err != nil {
-		return containersByEvictUnit{}, []containerGCInfo{}, err
-	}
-
-	unidentifiedContainers := make([]containerGCInfo, 0)
-	evictUnits := make(containersByEvictUnit)
-	newestGCTime := time.Now().Add(-cgc.policy.MinAge)
-	for _, container := range containers {
-		// Prune out running containers.
-		data, err := cgc.dockerClient.InspectContainer(container.ID)
-		if err != nil {
-			// Container may have been removed already, skip.
-			continue
-		} else if data.State.Running {
-			continue
-		} else if newestGCTime.Before(data.Created) {
-			continue
-		}
-
-		containerInfo := containerGCInfo{
-			id:         container.ID,
-			name:       container.Names[0],
-			createTime: data.Created,
-		}
-
-		containerName, _, err := dockertools.ParseDockerName(container.Names[0])
-
-		if err != nil {
-			unidentifiedContainers = append(unidentifiedContainers, containerInfo)
-		} else {
-			key := evictUnit{
-				uid:  containerName.PodUID,
-				name: containerName.ContainerName,
-			}
-			containerInfo.podNameWithNamespace = containerName.PodFullName
-			containerInfo.containerName = containerName.ContainerName
-			evictUnits[key] = append(evictUnits[key], containerInfo)
-		}
-	}
-
-	// Sort the containers by age.
-	for uid := range evictUnits {
-		sort.Sort(byCreated(evictUnits[uid]))
-	}
-
-	return evictUnits, unidentifiedContainers, nil
+	return cgc.runtime.GarbageCollect(cgc.policy.MaxPerPodContainer, cgc.policy.MaxContainers, cgc.policy.MinAge)
 }

pkg/kubelet/kubelet.go

@@ -236,11 +236,6 @@ func NewMainKubelet(
 		Namespace: "",
 	}
 
-	containerGC, err := newContainerGC(dockerClient, containerGCPolicy)
-	if err != nil {
-		return nil, err
-	}
-
 	diskSpaceManager, err := newDiskSpaceManager(cadvisorInterface, diskSpacePolicy)
 	if err != nil {
 		return nil, fmt.Errorf("failed to initialize disk manager: %v", err)
@@ -275,7 +270,6 @@ func NewMainKubelet(
 		streamingConnectionIdleTimeout: streamingConnectionIdleTimeout,
 		recorder:                       recorder,
 		cadvisor:                       cadvisorInterface,
-		containerGC:                    containerGC,
 		diskSpaceManager:               diskSpaceManager,
 		statusManager:                  statusManager,
 		volumeManager:                  volumeManager,
@@ -361,6 +355,13 @@ func NewMainKubelet(
 		return nil, fmt.Errorf("unsupported container runtime %q specified", containerRuntime)
 	}
 
+	// setup containerGC
+	containerGC, err := newContainerGC(klet.containerRuntime, containerGCPolicy)
+	if err != nil {
+		return nil, err
+	}
+	klet.containerGC = containerGC
+
 	// setup imageManager
 	imageManager, err := newImageManager(klet.containerRuntime, cadvisorInterface, recorder, nodeRef, imageGCPolicy)
 	if err != nil {