add /containerStats

pkg/api/types.go

@@ -66,6 +66,20 @@ type Container struct {
 	VolumeMounts []VolumeMount `yaml:"volumeMounts,omitempty" json:"volumeMounts,omitempty"`
 }
 
+// Percentile represents a pair which contains a percentage from 0 to 100 and
+// its corresponding value.
+type Percentile struct {
+	Percentage int    `json:"percentage,omitempty"`
+	Value      uint64 `json:"value,omitempty"`
+}
+
+// ContainerStats represents statistical information of a container
+type ContainerStats struct {
+	CpuUsagePercentiles    []Percentile `json:"cpu_usage_percentiles,omitempty"`
+	MemoryUsagePercentiles []Percentile `json:"memory_usage_percentiles,omitempty"`
+	MaxMemoryUsage         uint64       `json:"max_memory_usage,omitempty"`
+}
+
 // Event is the representation of an event logged to etcd backends
 type Event struct {
 	Event     string             `json:"event,omitempty"`

pkg/kubelet/kubelet.go

@@ -34,8 +34,8 @@ import (
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/third_party/src/github.com/fsouza/go-dockerclient"
 	"github.com/coreos/go-etcd/etcd"
-	"github.com/fsouza/go-dockerclient"
 	"github.com/google/cadvisor/info"
 	"gopkg.in/v1/yaml"
 )
@@ -650,3 +650,46 @@ func (kl *Kubelet) GetContainerInfo(name string) (string, error) {
 	data, err := json.Marshal(info)
 	return string(data), err
 }
+
+func (kl *Kubelet) GetContainerStats(name string) (*api.ContainerStats, error) {
+	if kl.CadvisorClient == nil {
+		return nil, nil
+	}
+	id, found, err := kl.GetContainerID(name)
+	if err != nil {
+		return nil, err
+	}
+	if !found {
+		return nil, nil
+	}
+
+	path := fmt.Sprintf("/docker/%v", id)
+	info, err := kl.CadvisorClient.ContainerInfo(path)
+
+	if err != nil {
+		return nil, err
+	}
+	if info.StatsPercentiles == nil {
+		return nil, nil
+	}
+
+	ret := new(api.ContainerStats)
+	ret.MaxMemoryUsage = info.StatsPercentiles.MaxMemoryUsage
+	if len(info.StatsPercentiles.CpuUsagePercentiles) > 0 {
+		percentiles := make([]api.Percentile, len(info.StatsPercentiles.CpuUsagePercentiles))
+		for i, p := range info.StatsPercentiles.CpuUsagePercentiles {
+			percentiles[i].Percentage = p.Percentage
+			percentiles[i].Value = p.Value
+		}
+		ret.CpuUsagePercentiles = percentiles
+	}
+	if len(info.StatsPercentiles.MemoryUsagePercentiles) > 0 {
+		percentiles := make([]api.Percentile, len(info.StatsPercentiles.MemoryUsagePercentiles))
+		for i, p := range info.StatsPercentiles.MemoryUsagePercentiles {
+			percentiles[i].Percentage = p.Percentage
+			percentiles[i].Value = p.Value
+		}
+		ret.MemoryUsagePercentiles = percentiles
+	}
+	return ret, nil
+}

pkg/kubelet/kubelet_server.go

@@ -17,6 +17,7 @@ limitations under the License.
 package kubelet
 
 import (
+	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -35,6 +36,7 @@ type KubeletServer struct {
 // For testablitiy.
 type kubeletInterface interface {
 	GetContainerID(name string) (string, bool, error)
+	GetContainerStats(name string) (*api.ContainerStats, error)
 	GetContainerInfo(name string) (string, error)
 }
 
@@ -64,6 +66,33 @@ func (s *KubeletServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			return
 		}
 		s.UpdateChannel <- manifest
+	case u.Path == "/containerStats":
+		container := u.Query().Get("container")
+		if len(container) == 0 {
+			w.WriteHeader(http.StatusBadRequest)
+			fmt.Fprint(w, "Missing container query arg.")
+			return
+		}
+		stats, err := s.Kubelet.GetContainerStats(container)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			fmt.Fprintf(w, "Internal Error: %#v", err)
+			return
+		}
+		if stats == nil {
+			w.WriteHeader(http.StatusOK)
+			fmt.Fprint(w, "{}")
+			return
+		}
+		w.Header().Add("Content-type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		encoder := json.NewEncoder(w)
+		err = encoder.Encode(stats)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			fmt.Fprintf(w, "Internal Error: %#v", err)
+			return
+		}
 	case u.Path == "/containerInfo":
 		container := u.Query().Get("container")
 		if len(container) == 0 {