Add initial container implementation.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/container_list.go

@@ -17,14 +17,87 @@ limitations under the License.
 package server
 
 import (
-	"errors"
+	"fmt"
 
+	"github.com/golang/glog"
 	"golang.org/x/net/context"
 
 	"k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+
+	"github.com/kubernetes-incubator/cri-containerd/pkg/metadata"
 )
 
 // ListContainers lists all containers matching the filter.
-func (c *criContainerdService) ListContainers(ctx context.Context, r *runtime.ListContainersRequest) (*runtime.ListContainersResponse, error) {
-	return nil, errors.New("not implemented")
+func (c *criContainerdService) ListContainers(ctx context.Context, r *runtime.ListContainersRequest) (retRes *runtime.ListContainersResponse, retErr error) {
+	glog.V(4).Infof("ListContainers with filter %+v", r.GetFilter())
+	defer func() {
+		if retErr == nil {
+			glog.V(4).Infof("ListContainers returns containers %+v", retRes.GetContainers())
+		}
+	}()
+
+	// List all container metadata from store.
+	metas, err := c.containerStore.List()
+	if err != nil {
+		return nil, fmt.Errorf("failed to list metadata from container store: %v", err)
+	}
+
+	var containers []*runtime.Container
+	for _, meta := range metas {
+		containers = append(containers, toCRIContainer(meta))
+	}
+
+	containers = c.filterCRIContainers(containers, r.GetFilter())
+	return &runtime.ListContainersResponse{Containers: containers}, nil
+}
+
+// toCRIContainer converts container metadata into CRI container.
+func toCRIContainer(meta *metadata.ContainerMetadata) *runtime.Container {
+	return &runtime.Container{
+		Id:           meta.ID,
+		PodSandboxId: meta.SandboxID,
+		Metadata:     meta.Config.GetMetadata(),
+		Image:        meta.Config.GetImage(),
+		ImageRef:     meta.ImageRef,
+		State:        meta.State(),
+		CreatedAt:    meta.CreatedAt,
+		Labels:       meta.Config.GetLabels(),
+		Annotations:  meta.Config.GetAnnotations(),
+	}
+}
+
+// filterCRIContainers filters CRIContainers.
+func (c *criContainerdService) filterCRIContainers(containers []*runtime.Container, filter *runtime.ContainerFilter) []*runtime.Container {
+	if filter == nil {
+		return containers
+	}
+
+	filtered := []*runtime.Container{}
+	for _, cntr := range containers {
+		if filter.GetId() != "" && filter.GetId() != cntr.Id {
+			continue
+		}
+		if filter.GetPodSandboxId() != "" && filter.GetPodSandboxId() != cntr.PodSandboxId {
+			continue
+		}
+		if filter.GetState() != nil && filter.GetState().GetState() != cntr.State {
+			continue
+		}
+		if filter.GetLabelSelector() != nil {
+			match := true
+			for k, v := range filter.GetLabelSelector() {
+				got, ok := cntr.Labels[k]
+				if !ok || got != v {
+					match = false
+					break
+				}
+			}
+			if !match {
+				continue
+			}
+		}
+		filtered = append(filtered, cntr)
+	}
+
+	return filtered
 }