Adding container metrics

Signed-off-by: Abhinandan Prativadi <abhi@docker.com>

pkg/server/container_stats.go

@@ -17,15 +17,34 @@ limitations under the License.
 package server
 
 import (
-	"errors"
+	"fmt"
 
+	tasks "github.com/containerd/containerd/api/services/tasks/v1"
 	"golang.org/x/net/context"
-
 	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 )
 
 // ContainerStats returns stats of the container. If the container does not
 // exist, the call returns an error.
 func (c *criContainerdService) ContainerStats(ctx context.Context, in *runtime.ContainerStatsRequest) (*runtime.ContainerStatsResponse, error) {
-	return nil, errors.New("not implemented")
+	// Validate the stats request
+	if in.GetContainerId() == "" {
+		return nil, fmt.Errorf("invalid container stats request")
+	}
+	containerID := in.GetContainerId()
+	_, err := c.containerStore.Get(containerID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to find container %q: %v", containerID, err)
+	}
+	request := &tasks.MetricsRequest{Filters: []string{"id==" + containerID}}
+	resp, err := c.taskService.Metrics(ctx, request)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch metrics for tasks: %v", err)
+	}
+
+	var cs runtime.ContainerStats
+	if err := c.getContainerMetrics(containerID, resp.Metrics[0], &cs); err != nil {
+		return nil, fmt.Errorf("failed to decode container metrics: %v", err)
+	}
+	return &runtime.ContainerStatsResponse{Stats: &cs}, nil
 }

pkg/server/container_stats_list.go

@@ -17,14 +17,156 @@ limitations under the License.
 package server
 
 import (
-	"errors"
+	"fmt"
 
+	"github.com/containerd/cgroups"
+	tasks "github.com/containerd/containerd/api/services/tasks/v1"
+	"github.com/containerd/containerd/api/types"
+	"github.com/containerd/typeurl"
+	"github.com/golang/glog"
 	"golang.org/x/net/context"
-
 	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 )
 
 // ListContainerStats returns stats of all running containers.
-func (c *criContainerdService) ListContainerStats(ctx context.Context, in *runtime.ListContainerStatsRequest) (*runtime.ListContainerStatsResponse, error) {
-	return nil, errors.New("not implemented")
+func (c *criContainerdService) ListContainerStats(
+	ctx context.Context,
+	in *runtime.ListContainerStatsRequest,
+) (*runtime.ListContainerStatsResponse, error) {
+	request, candidateContainers, err := c.buildTaskMetricsRequest(in)
+	if err != nil {
+		return nil, fmt.Errorf("failed to build metrics request: %v", err)
+	}
+	resp, err := c.taskService.Metrics(ctx, &request)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch metrics for tasks: %v", err)
+	}
+	criStats, err := c.toCRIContainerStats(resp.Metrics, candidateContainers)
+	if err != nil {
+		return nil, fmt.Errorf("failed to convert to cri containerd stats format: %v", err)
+	}
+	return criStats, nil
+}
+
+func (c *criContainerdService) toCRIContainerStats(
+	stats []*types.Metric,
+	candidateContainers map[string]bool,
+) (*runtime.ListContainerStatsResponse, error) {
+	containerStats := new(runtime.ListContainerStatsResponse)
+	for _, stat := range stats {
+		var cs runtime.ContainerStats
+		if err := c.getContainerMetrics(stat.ID, stat, &cs); err != nil {
+			glog.Errorf("failed to decode container metrics: %v", err)
+			continue
+		}
+		delete(candidateContainers, stat.ID)
+		containerStats.Stats = append(containerStats.Stats, &cs)
+	}
+	// If there is a state where containers are dead at the time of query
+	// but not removed, then check if the writeableLayer information
+	// is present and attach the same.
+	for id := range candidateContainers {
+		var cs runtime.ContainerStats
+		if err := c.getContainerMetrics(id, nil, &cs); err != nil {
+			glog.Errorf("failed to decode container metrics: %v", err)
+			continue
+		}
+		containerStats.Stats = append(containerStats.Stats, &cs)
+	}
+	return containerStats, nil
+}
+
+func (c *criContainerdService) getContainerMetrics(
+	containerID string,
+	stats *types.Metric,
+	cs *runtime.ContainerStats,
+) error {
+	var usedBytes, inodesUsed uint64
+	sn, err := c.snapshotStore.Get(containerID)
+	// If snapshotstore doesn't have cached snapshot information
+	// set WritableLayer usage to zero
+	if err == nil {
+		inodesUsed = sn.Size
+		usedBytes = sn.Inodes
+	}
+	cs.WritableLayer = &runtime.FilesystemUsage{
+		Timestamp: sn.Timestamp,
+		StorageId: &runtime.StorageIdentifier{
+			Uuid: c.imageFSUUID,
+		},
+		UsedBytes:  &runtime.UInt64Value{usedBytes},
+		InodesUsed: &runtime.UInt64Value{inodesUsed},
+	}
+
+	// Get the container from store and extract the attributes
+	cnt, err := c.containerStore.Get(containerID)
+	if err != nil {
+		return fmt.Errorf("failed to find container %q in container store: %v", containerID, err)
+	}
+	cs.Attributes = &runtime.ContainerAttributes{
+		Id:          containerID,
+		Metadata:    cnt.Config.GetMetadata(),
+		Labels:      cnt.Config.GetLabels(),
+		Annotations: cnt.Config.GetAnnotations(),
+	}
+
+	if stats != nil {
+		s, err := typeurl.UnmarshalAny(stats.Data)
+		if err != nil {
+			return fmt.Errorf("failed to extract container metrics: %v", err)
+		}
+		metrics := s.(*cgroups.Metrics)
+		cs.Cpu = &runtime.CpuUsage{
+			Timestamp:            stats.Timestamp.Unix(),
+			UsageCoreNanoSeconds: &runtime.UInt64Value{metrics.CPU.Usage.Total},
+		}
+		cs.Memory = &runtime.MemoryUsage{
+			Timestamp:       stats.Timestamp.Unix(),
+			WorkingSetBytes: &runtime.UInt64Value{metrics.Memory.Usage.Usage},
+		}
+	}
+
+	return nil
+}
+
+// buildTaskMetricsRequest constructs a tasks.MetricsRequest based on
+// the information in the stats request and the containerStore
+func (c *criContainerdService) buildTaskMetricsRequest(
+	r *runtime.ListContainerStatsRequest,
+) (tasks.MetricsRequest, map[string]bool, error) {
+	var req tasks.MetricsRequest
+	if r.GetFilter == nil {
+		return req, nil, nil
+	}
+
+	candidateContainers := make(map[string]bool)
+	for _, c := range c.containerStore.List() {
+		if r.Filter.GetId() != "" && c.ID != r.Filter.GetId() {
+			continue
+		}
+		if r.Filter.GetPodSandboxId() != "" && c.SandboxID != r.Filter.GetPodSandboxId() {
+			continue
+		}
+		if r.Filter.GetLabelSelector() != nil && !matchLabelSelector(r.Filter.GetLabelSelector(), c.Config.GetLabels()) {
+			continue
+		}
+		candidateContainers[c.ID] = true
+	}
+	for id := range candidateContainers {
+		req.Filters = append(req.Filters, "id=="+id)
+	}
+	return req, candidateContainers, nil
+}
+
+func matchLabelSelector(selector, labels map[string]string) bool {
+	for k, v := range selector {
+		if val, ok := labels[k]; ok {
+			if v != val {
+				return false
+			}
+		} else {
+			return false
+		}
+	}
+	return true
 }