Merge pull request #4872 from vrothberg/v2-stats

v2 api: stats improvements

pkg/api/handlers/generic/containers_stats.go

@@ -43,28 +43,26 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// If the container isn't returning, then let's not bother and return
+	// immediately.
 	state, err := ctnr.State()
 	if err != nil {
 		utils.InternalServerError(w, err)
 		return
 	}
 	if state != define.ContainerStateRunning && !query.Stream {
-		utils.WriteJSON(w, http.StatusOK, &handlers.Stats{StatsJSON: docker.StatsJSON{
-			Name: ctnr.Name(),
-			ID:   ctnr.ID(),
-		}})
+		utils.InternalServerError(w, define.ErrCtrStateInvalid)
 		return
 	}
 
-	var preRead time.Time
-	var preCPUStats docker.CPUStats
-
 	stats, err := ctnr.GetContainerStats(&libpod.ContainerStats{})
 	if err != nil {
 		utils.InternalServerError(w, errors.Wrapf(err, "Failed to obtain Container %s stats", name))
 		return
 	}
 
+	var preRead time.Time
+	var preCPUStats docker.CPUStats
 	if query.Stream {
 		preRead = time.Now()
 		preCPUStats = docker.CPUStats{
@@ -78,25 +76,44 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 			OnlineCPUs:     0,
 			ThrottlingData: docker.ThrottlingData{},
 		}
-		time.Sleep(DefaultStatsPeriod)
 	}
 
-	cgroupPath, _ := ctnr.CGroupPath()
-	cgroup, _ := cgroups.Load(cgroupPath)
-
 	for ok := true; ok; ok = query.Stream {
-		state, _ := ctnr.State()
-		if state != define.ContainerStateRunning {
-			time.Sleep(10 * time.Second)
-			continue
+		// Container stats
+		stats, err := ctnr.GetContainerStats(stats)
+		if err != nil {
+			utils.InternalServerError(w, err)
+			return
+		}
+		inspect, err := ctnr.Inspect(false)
+		if err != nil {
+			utils.InternalServerError(w, err)
+			return
+		}
+		// Cgroup stats
+		cgroupPath, err := ctnr.CGroupPath()
+		if err != nil {
+			utils.InternalServerError(w, err)
+			return
+		}
+		cgroup, err := cgroups.Load(cgroupPath)
+		if err != nil {
+			utils.InternalServerError(w, err)
+			return
+		}
+		cgroupStat, err := cgroup.Stat()
+		if err != nil {
+			utils.InternalServerError(w, err)
+			return
 		}
 
-		stats, _ := ctnr.GetContainerStats(stats)
-		cgroupStat, _ := cgroup.Stat()
-		inspect, _ := ctnr.Inspect(false)
-
+		// FIXME: network inspection does not yet work entirely
 		net := make(map[string]docker.NetworkStats)
-		net[inspect.NetworkSettings.EndpointID] = docker.NetworkStats{
+		networkName := inspect.NetworkSettings.EndpointID
+		if networkName == "" {
+			networkName = "network"
+		}
+		net[networkName] = docker.NetworkStats{
 			RxBytes:    stats.NetInput,
 			RxPackets:  0,
 			RxErrors:   0,
@@ -127,13 +144,6 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 					IoTimeRecursive:         nil,
 					SectorsRecursive:        nil,
 				},
-				NumProcs: 0,
-				StorageStats: docker.StorageStats{
-					ReadCountNormalized:  0,
-					ReadSizeBytes:        0,
-					WriteCountNormalized: 0,
-					WriteSizeBytes:       0,
-				},
 				CPUStats: docker.CPUStats{
 					CPUUsage: docker.CPUUsage{
 						TotalUsage:        cgroupStat.CPU.Usage.Total,
@@ -174,17 +184,21 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 		preRead = s.Read
 		bits, err := json.Marshal(s.CPUStats)
 		if err != nil {
-			logrus.Errorf("unable to marshal cpu stats: %q", err)
+			logrus.Errorf("Unable to marshal cpu stats: %q", err)
 		}
 		if err := json.Unmarshal(bits, &preCPUStats); err != nil {
-			logrus.Errorf("unable to unmarshal previous stats: %q", err)
+			logrus.Errorf("Unable to unmarshal previous stats: %q", err)
+		}
+
+		// Only sleep when we're streaming.
+		if query.Stream {
+			time.Sleep(DefaultStatsPeriod)
 		}
-		time.Sleep(DefaultStatsPeriod)
 	}
 }
 
 func toBlkioStatEntry(entries []cgroups.BlkIOEntry) []docker.BlkioStatEntry {
-	results := make([]docker.BlkioStatEntry, 0, len(entries))
+	results := make([]docker.BlkioStatEntry, len(entries))
 	for i, e := range entries {
 		bits, err := json.Marshal(e)
 		if err != nil {

pkg/api/handlers/libpod/containers.go

@@ -143,9 +143,7 @@ func LogsFromContainer(w http.ResponseWriter, r *http.Request) {
 	// timestamps
 	// tail string
 }
-func StatsContainer(w http.ResponseWriter, r *http.Request) {
-	//stream
-}
+
 func CreateContainer(w http.ResponseWriter, r *http.Request) {
 
 }

pkg/api/handlers/utils/handler.go

@@ -33,6 +33,7 @@ func WriteResponse(w http.ResponseWriter, code int, value interface{}) {
 }
 
 func WriteJSON(w http.ResponseWriter, code int, value interface{}) {
+	// FIXME: we don't need to write the header in all/some circumstances.
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(code)
 

pkg/api/server/register_containers.go

@@ -629,7 +629,30 @@ func (s *APIServer) RegisterContainersHandlers(r *mux.Router) error {
 	//   '500':
 	//      "$ref": "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/start"), APIHandler(s.Context, handlers.StartContainer)).Methods(http.MethodPost)
-	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/stats"), APIHandler(s.Context, libpod.StatsContainer)).Methods(http.MethodGet)
+	// swagger:operation GET /libpod/containers/{nameOrID}/stats containers statsContainer
+	// ---
+	// summary: Get stats for a container
+	// description: This returns a live stream of a container’s resource usage statistics.
+	// parameters:
+	//  - in: path
+	//    name: nameOrID
+	//    required: true
+	//    description: the name or ID of the container
+	//  - in: query
+	//    name: stream
+	//    type: bool
+	//    default: true
+	//    description: Stream the output
+	// produces:
+	// - application/json
+	// responses:
+	//   '200':
+	//     description: no error
+	//   '404':
+	//       "$ref": "#/responses/NoSuchContainer"
+	//   '500':
+	//      "$ref": "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/stats"), APIHandler(s.Context, generic.StatsContainer)).Methods(http.MethodGet)
 	r.HandleFunc(VersionedPath("/libpod/containers/{name:..*}/top"), APIHandler(s.Context, handlers.TopContainer)).Methods(http.MethodGet)
 	// swagger:operation POST /libpod/containers/{nameOrID}/unpause containers libpodUnpauseContainer
 	// ---