Merge pull request #515 from rjnagal/summary

Expose a minimal 2.0 API with the first summary endpoint.

api/versions.go

@@ -28,6 +28,7 @@ const (
 	subcontainersApi = "subcontainers"
 	machineApi       = "machine"
 	dockerApi        = "docker"
+	summaryApi       = "summary"
 )
 
 // Interface for a cAdvisor API version
@@ -47,7 +48,8 @@ func getApiVersions() []ApiVersion {
 	v1_0 := &version1_0{}
 	v1_1 := newVersion1_1(v1_0)
 	v1_2 := newVersion1_2(v1_1)
-	return []ApiVersion{v1_0, v1_1, v1_2}
+	v2_0 := newVersion2_0(v1_2)
+	return []ApiVersion{v1_0, v1_1, v1_2, v2_0}
 }
 
 // API v1.0
@@ -64,8 +66,8 @@ func (self *version1_0) SupportedRequestTypes() []string {
 }
 
 func (self *version1_0) HandleRequest(requestType string, request []string, m manager.Manager, w http.ResponseWriter, r *http.Request) error {
-	switch {
+	switch requestType {
-	case requestType == machineApi:
+	case machineApi:
 		glog.V(2).Infof("Api - Machine")
 
 		// Get the MachineInfo
@@ -78,7 +80,7 @@ func (self *version1_0) HandleRequest(requestType string, request []string, m ma
 		if err != nil {
 			return err
 		}
-	case requestType == containersApi:
+	case containersApi:
 		containerName := getContainerName(request)
 		glog.V(2).Infof("Api - Container(%s)", containerName)
 
@@ -127,8 +129,8 @@ func (self *version1_1) SupportedRequestTypes() []string {
 }
 
 func (self *version1_1) HandleRequest(requestType string, request []string, m manager.Manager, w http.ResponseWriter, r *http.Request) error {
-	switch {
+	switch requestType {
-	case requestType == subcontainersApi:
+	case subcontainersApi:
 		containerName := getContainerName(request)
 		glog.V(2).Infof("Api - Subcontainers(%s)", containerName)
 
@@ -177,8 +179,8 @@ func (self *version1_2) SupportedRequestTypes() []string {
 }
 
 func (self *version1_2) HandleRequest(requestType string, request []string, m manager.Manager, w http.ResponseWriter, r *http.Request) error {
-	switch {
+	switch requestType {
-	case requestType == dockerApi:
+	case dockerApi:
 		glog.V(2).Infof("Api - Docker(%v)", request)
 
 		// Get the query request.
@@ -223,3 +225,39 @@ func (self *version1_2) HandleRequest(requestType string, request []string, m ma
 		return self.baseVersion.HandleRequest(requestType, request, m, w, r)
 	}
 }
+
+// v2.0 builds on v1.2
+type version2_0 struct {
+	baseVersion *version1_2
+}
+
+func newVersion2_0(v *version1_2) *version2_0 {
+	return &version2_0{
+		baseVersion: v,
+	}
+}
+
+func (self *version2_0) Version() string {
+	return "v2.0"
+}
+
+func (self *version2_0) SupportedRequestTypes() []string {
+	return append(self.baseVersion.SupportedRequestTypes(), summaryApi)
+}
+
+func (self *version2_0) HandleRequest(requestType string, request []string, m manager.Manager, w http.ResponseWriter, r *http.Request) error {
+	switch requestType {
+	case summaryApi:
+		containerName := getContainerName(request)
+		glog.V(2).Infof("Api - Summary(%v)", containerName)
+
+		stats, err := m.GetContainerDerivedStats(containerName)
+		if err != nil {
+			return err
+		}
+
+		return writeResult(stats, w)
+	default:
+		return self.baseVersion.HandleRequest(requestType, request, m, w, r)
+	}
+}

manager/container.go

@@ -100,6 +100,13 @@ func (c *containerData) GetInfo() (*containerInfo, error) {
 	return &c.info, nil
 }
 
+func (c *containerData) DerivedStats() (info.DerivedStats, error) {
+	if c.summaryReader == nil {
+		return info.DerivedStats{}, fmt.Errorf("derived stats not enabled for container %q", c.info.Name)
+	}
+	return c.summaryReader.DerivedStats()
+}
+
 func newContainerData(containerName string, driver storage.StorageDriver, handler container.ContainerHandler, loadReader cpuload.CpuLoadReader, logUsage bool) (*containerData, error) {
 	if driver == nil {
 		return nil, fmt.Errorf("nil storage driver")

manager/manager.go

@@ -58,6 +58,9 @@ type Manager interface {
 	// Gets information about a specific Docker container. The specified name is within the Docker namespace.
 	DockerContainer(dockerName string, query *info.ContainerInfoRequest) (info.ContainerInfo, error)
 
+	// Get derived stats for a container.
+	GetContainerDerivedStats(containerName string) (info.DerivedStats, error)
+
 	// Get information about the machine.
 	GetMachineInfo() (*info.MachineInfo, error)
 
@@ -364,6 +367,20 @@ func (self *manager) containerDataSliceToContainerInfoSlice(containers []*contai
 	return output, nil
 }
 
+func (self *manager) GetContainerDerivedStats(containerName string) (info.DerivedStats, error) {
+	var ok bool
+	var cont *containerData
+	func() {
+		self.containersLock.RLock()
+		defer self.containersLock.RUnlock()
+		cont, ok = self.containers[namespacedContainerName{Name: containerName}]
+	}()
+	if !ok {
+		return info.DerivedStats{}, fmt.Errorf("unknown container %q", containerName)
+	}
+	return cont.DerivedStats()
+}
+
 func (m *manager) GetMachineInfo() (*info.MachineInfo, error) {
 	// Copy and return the MachineInfo.
 	return &m.machineInfo, nil

summary/summary.go

@@ -57,6 +57,7 @@ type StatsSummary struct {
 // stats are updated.
 func (s *StatsSummary) AddSample(stat info.ContainerStats) error {
 	sample := secondSample{}
+	sample.Timestamp = stat.Timestamp
 	if s.available.Cpu {
 		sample.Cpu = stat.Cpu.Usage.Total
 	}
@@ -119,7 +120,7 @@ func (s *StatsSummary) getDerivedUsage(n int) (info.Usage, error) {
 	// We generate derived stats even with partial data.
 	usage := GetDerivedPercentiles(samples)
 	// Assumes we have equally placed minute samples.
-	usage.PercentComplete = int32(numSamples / n)
+	usage.PercentComplete = int32(numSamples * 100 / n)
 	return usage, nil
 }