Merge pull request #7753 from vrothberg/fix-7689

remote stats

cmd/podman/containers/stats.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"os"
 	"strings"
-	"sync"
 	"text/tabwriter"
 	"text/template"
 
@@ -48,8 +47,18 @@ var (
 	}
 )
 
+// statsOptionsCLI is used for storing CLI arguments. Some fields are later
+// used in the backend.
+type statsOptionsCLI struct {
+	All      bool
+	Format   string
+	Latest   bool
+	NoReset  bool
+	NoStream bool
+}
+
 var (
-	statsOptions       entities.ContainerStatsOptions
+	statsOptions       statsOptionsCLI
 	defaultStatsRow    = "{{.ID}}\t{{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.MemPerc}}\t{{.NetIO}}\t{{.BlockIO}}\t{{.PIDS}}\n"
 	defaultStatsHeader = "ID\tNAME\tCPU %\tMEM USAGE / LIMIT\tMEM %\tNET IO\tBLOCK IO\tPIDS\n"
 )
@@ -107,32 +116,37 @@ func stats(cmd *cobra.Command, args []string) error {
 			return errors.New("stats is not supported in rootless mode without cgroups v2")
 		}
 	}
-	statsOptions.StatChan = make(chan []*define.ContainerStats, 1)
-	wg := sync.WaitGroup{}
-	wg.Add(1)
-	go func() {
-		for reports := range statsOptions.StatChan {
-			if err := outputStats(reports); err != nil {
+
+	// Convert to the entities options.  We should not leak CLI-only
+	// options into the backend and separate concerns.
+	opts := entities.ContainerStatsOptions{
+		Latest: statsOptions.Latest,
+		Stream: !statsOptions.NoStream,
+	}
+	statsChan, err := registry.ContainerEngine().ContainerStats(registry.Context(), args, opts)
+	if err != nil {
+		return err
+	}
+	for report := range statsChan {
+		if report.Error != nil {
+			return report.Error
+		}
+		if err := outputStats(report.Stats); err != nil {
 			logrus.Error(err)
 		}
 	}
-		wg.Done()
-
-	}()
-	err := registry.ContainerEngine().ContainerStats(registry.Context(), args, statsOptions)
-	wg.Wait()
-	return err
+	return nil
 }
 
-func outputStats(reports []*define.ContainerStats) error {
+func outputStats(reports []define.ContainerStats) error {
 	if len(statsOptions.Format) < 1 && !statsOptions.NoReset {
 		tm.Clear()
 		tm.MoveCursor(1, 1)
 		tm.Flush()
 	}
-	stats := make([]*containerStats, 0, len(reports))
+	stats := make([]containerStats, 0, len(reports))
 	for _, r := range reports {
-		stats = append(stats, &containerStats{r})
+		stats = append(stats, containerStats{r})
 	}
 	if statsOptions.Format == "json" {
 		return outputJSON(stats)
@@ -163,7 +177,7 @@ func outputStats(reports []*define.ContainerStats) error {
 }
 
 type containerStats struct {
-	*define.ContainerStats
+	define.ContainerStats
 }
 
 func (s *containerStats) ID() string {
@@ -213,7 +227,7 @@ func combineHumanValues(a, b uint64) string {
 	return fmt.Sprintf("%s / %s", units.HumanSize(float64(a)), units.HumanSize(float64(b)))
 }
 
-func outputJSON(stats []*containerStats) error {
+func outputJSON(stats []containerStats) error {
 	type jstat struct {
 		Id         string `json:"id"` //nolint
 		Name       string `json:"name"`

pkg/api/handlers/libpod/containers_stats.go

@@ -0,0 +1,72 @@
+package libpod
+
+import (
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"github.com/containers/podman/v2/libpod"
+	"github.com/containers/podman/v2/pkg/api/handlers/utils"
+	"github.com/containers/podman/v2/pkg/domain/entities"
+	"github.com/containers/podman/v2/pkg/domain/infra/abi"
+	"github.com/gorilla/schema"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const DefaultStatsPeriod = 5 * time.Second
+
+func StatsContainer(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
+
+	query := struct {
+		Containers []string `schema:"containers"`
+		Stream     bool     `schema:"stream"`
+	}{
+		Stream: true,
+	}
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		utils.Error(w, "Something went wrong.", http.StatusBadRequest, errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String()))
+		return
+	}
+
+	// Reduce code duplication and use the local/abi implementation of
+	// container stats.
+	containerEngine := abi.ContainerEngine{Libpod: runtime}
+
+	statsOptions := entities.ContainerStatsOptions{
+		Stream: query.Stream,
+	}
+
+	// Stats will stop if the connection is closed.
+	statsChan, err := containerEngine.ContainerStats(r.Context(), query.Containers, statsOptions)
+	if err != nil {
+		utils.InternalServerError(w, err)
+		return
+	}
+
+	// Write header and content type.
+	w.WriteHeader(http.StatusOK)
+	w.Header().Add("Content-Type", "application/json")
+	if flusher, ok := w.(http.Flusher); ok {
+		flusher.Flush()
+	}
+
+	// Setup JSON encoder for streaming.
+	coder := json.NewEncoder(w)
+	coder.SetEscapeHTML(true)
+
+	for stats := range statsChan {
+		if err := coder.Encode(stats); err != nil {
+			// Note: even when streaming, the stats goroutine will
+			// be notified (and stop) as the connection will be
+			// closed.
+			logrus.Errorf("Unable to encode stats: %v", err)
+			return
+		}
+		if flusher, ok := w.(http.Flusher); ok {
+			flusher.Flush()
+		}
+	}
+}

pkg/api/server/register_containers.go

@@ -1013,7 +1013,7 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	// tags:
 	//  - containers
 	// summary: Get stats for a container
-	// description: This returns a live stream of a container’s resource usage statistics.
+	// description: DEPRECATED. This endpoint will be removed with the next major release. Please use /libpod/containers/stats instead.
 	// parameters:
 	//  - in: path
 	//    name: name
@@ -1035,6 +1035,35 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/containers/{name}/stats"), s.APIHandler(compat.StatsContainer)).Methods(http.MethodGet)
+	// swagger:operation GET /libpod/containers/stats libpod libpodStatsContainers
+	// ---
+	// tags:
+	//  - containers
+	// summary: Get stats for one or more containers
+	// description: Return a live stream of resource usage statistics of one or more container. If no container is specified, the statistics of all containers are returned.
+	// parameters:
+	//  - in: query
+	//    name: containers
+	//    description: names or IDs of containers
+	//    type: array
+	//    items:
+	//       type: string
+	//  - in: query
+	//    name: stream
+	//    type: boolean
+	//    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/stats"), s.APIHandler(libpod.StatsContainer)).Methods(http.MethodGet)
+
 	// swagger:operation GET /libpod/containers/{name}/top libpod libpodTopContainer
 	// ---
 	// tags:

pkg/bindings/containers/containers.go

@@ -197,7 +197,56 @@ func Start(ctx context.Context, nameOrID string, detachKeys *string) error {
 	return response.Process(nil)
 }
 
-func Stats() {}
+func Stats(ctx context.Context, containers []string, stream *bool) (chan entities.ContainerStatsReport, error) {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+	params := url.Values{}
+	if stream != nil {
+		params.Set("stream", strconv.FormatBool(*stream))
+	}
+	for _, c := range containers {
+		params.Add("containers", c)
+	}
+
+	response, err := conn.DoRequest(nil, http.MethodGet, "/containers/stats", params, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	statsChan := make(chan entities.ContainerStatsReport)
+
+	go func() {
+		defer close(statsChan)
+
+		dec := json.NewDecoder(response.Body)
+		doStream := true
+		if stream != nil {
+			doStream = *stream
+		}
+
+	streamLabel: // label to flatten the scope
+		select {
+		case <-response.Request.Context().Done():
+			return // lost connection - maybe the server quit
+		default:
+			// fall through and do some work
+		}
+		var report entities.ContainerStatsReport
+		if err := dec.Decode(&report); err != nil {
+			report = entities.ContainerStatsReport{Error: err}
+		}
+		statsChan <- report
+
+		if report.Error != nil || !doStream {
+			return
+		}
+		goto streamLabel
+	}()
+
+	return statsChan, nil
+}
 
 // Top gathers statistics about the running processes in a container. The nameOrID can be a container name
 // or a partial/full ID.  The descriptors allow for specifying which data to collect from the process.

pkg/domain/entities/containers.go

@@ -411,10 +411,17 @@ type ContainerCpReport struct {
 // ContainerStatsOptions describes input options for getting
 // stats on containers
 type ContainerStatsOptions struct {
-	All      bool
-	Format   string
+	// Operate on the latest known container.  Only supported for local
+	// clients.
 	Latest bool
-	NoReset  bool
-	NoStream bool
-	StatChan chan []*define.ContainerStats
+	// Stream stats.
+	Stream bool
+}
+
+// ContainerStatsReport is used for streaming container stats.
+type ContainerStatsReport struct {
+	// Error from reading stats.
+	Error error
+	// Results, set when there is no error.
+	Stats []define.ContainerStats
 }

pkg/domain/entities/engine_container.go

@@ -38,7 +38,7 @@ type ContainerEngine interface {
 	ContainerRun(ctx context.Context, opts ContainerRunOptions) (*ContainerRunReport, error)
 	ContainerRunlabel(ctx context.Context, label string, image string, args []string, opts ContainerRunlabelOptions) error
 	ContainerStart(ctx context.Context, namesOrIds []string, options ContainerStartOptions) ([]*ContainerStartReport, error)
-	ContainerStats(ctx context.Context, namesOrIds []string, options ContainerStatsOptions) error
+	ContainerStats(ctx context.Context, namesOrIds []string, options ContainerStatsOptions) (chan ContainerStatsReport, error)
 	ContainerStop(ctx context.Context, namesOrIds []string, options StopOptions) ([]*StopReport, error)
 	ContainerTop(ctx context.Context, options TopOptions) (*StringSliceReport, error)
 	ContainerUnmount(ctx context.Context, nameOrIDs []string, options ContainerUnmountOptions) ([]*ContainerUnmountReport, error)

pkg/domain/infra/abi/containers.go

@@ -1142,12 +1142,12 @@ func (ic *ContainerEngine) Shutdown(_ context.Context) {
 	})
 }
 
-func (ic *ContainerEngine) ContainerStats(ctx context.Context, namesOrIds []string, options entities.ContainerStatsOptions) error {
-	defer close(options.StatChan)
+func (ic *ContainerEngine) ContainerStats(ctx context.Context, namesOrIds []string, options entities.ContainerStatsOptions) (statsChan chan entities.ContainerStatsReport, err error) {
+	statsChan = make(chan entities.ContainerStatsReport, 1)
+
 	containerFunc := ic.Libpod.GetRunningContainers
+	queryAll := false
 	switch {
-	case len(namesOrIds) > 0:
-		containerFunc = func() ([]*libpod.Container, error) { return ic.Libpod.GetContainersByList(namesOrIds) }
 	case options.Latest:
 		containerFunc = func() ([]*libpod.Container, error) {
 			lastCtr, err := ic.Libpod.GetLatestContainer()
@@ -1156,62 +1156,76 @@ func (ic *ContainerEngine) ContainerStats(ctx context.Context, namesOrIds []stri
 			}
 			return []*libpod.Container{lastCtr}, nil
 		}
-	case options.All:
+	case len(namesOrIds) > 0:
+		containerFunc = func() ([]*libpod.Container, error) { return ic.Libpod.GetContainersByList(namesOrIds) }
+	default:
+		// No containers, no latest -> query all!
+		queryAll = true
 		containerFunc = ic.Libpod.GetAllContainers
 	}
 
-	ctrs, err := containerFunc()
-	if err != nil {
-		return errors.Wrapf(err, "unable to get list of containers")
+	go func() {
+		defer close(statsChan)
+		var (
+			err            error
+			containers     []*libpod.Container
+			containerStats map[string]*define.ContainerStats
+		)
+		containerStats = make(map[string]*define.ContainerStats)
+
+	stream: // label to flatten the scope
+		select {
+		case <-ctx.Done():
+			// client cancelled
+			logrus.Debugf("Container stats stopped: context cancelled")
+			return
+		default:
+			// just fall through and do work
 		}
-	containerStats := map[string]*define.ContainerStats{}
-	for _, ctr := range ctrs {
-		initialStats, err := ctr.GetContainerStats(&define.ContainerStats{})
+
+		// Anonymous func to easily use the return values for streaming.
+		computeStats := func() ([]define.ContainerStats, error) {
+			containers, err = containerFunc()
+			if err != nil {
+				return nil, errors.Wrapf(err, "unable to get list of containers")
+			}
+
+			reportStats := []define.ContainerStats{}
+			for _, ctr := range containers {
+				prev, ok := containerStats[ctr.ID()]
+				if !ok {
+					prev = &define.ContainerStats{}
+				}
+
+				stats, err := ctr.GetContainerStats(prev)
 				if err != nil {
-			// when doing "all", don't worry about containers that are not running
 					cause := errors.Cause(err)
-			if options.All && (cause == define.ErrCtrRemoved || cause == define.ErrNoSuchCtr || cause == define.ErrCtrStateInvalid) {
+					if queryAll && (cause == define.ErrCtrRemoved || cause == define.ErrNoSuchCtr || cause == define.ErrCtrStateInvalid) {
 						continue
 					}
 					if cause == cgroups.ErrCgroupV1Rootless {
 						err = cause
 					}
-			return err
+					return nil, err
 				}
-		containerStats[ctr.ID()] = initialStats
+
+				containerStats[ctr.ID()] = stats
+				reportStats = append(reportStats, *stats)
 			}
-	for {
-		reportStats := []*define.ContainerStats{}
-		for _, ctr := range ctrs {
-			id := ctr.ID()
-			if _, ok := containerStats[ctr.ID()]; !ok {
-				initialStats, err := ctr.GetContainerStats(&define.ContainerStats{})
-				if errors.Cause(err) == define.ErrCtrRemoved || errors.Cause(err) == define.ErrNoSuchCtr || errors.Cause(err) == define.ErrCtrStateInvalid {
-					// skip dealing with a container that is gone
-					continue
+			return reportStats, nil
 		}
-				if err != nil {
-					return err
-				}
-				containerStats[id] = initialStats
-			}
-			stats, err := ctr.GetContainerStats(containerStats[id])
-			if err != nil && errors.Cause(err) != define.ErrNoSuchCtr {
-				return err
-			}
-			// replace the previous measurement with the current one
-			containerStats[id] = stats
-			reportStats = append(reportStats, stats)
-		}
-		ctrs, err = containerFunc()
-		if err != nil {
-			return err
-		}
-		options.StatChan <- reportStats
-		if options.NoStream {
-			break
+
+		report := entities.ContainerStatsReport{}
+		report.Stats, report.Error = computeStats()
+		statsChan <- report
+
+		if report.Error != nil || !options.Stream {
+			return
 		}
+
 		time.Sleep(time.Second)
-	}
-	return nil
+		goto stream
+	}()
+
+	return statsChan, nil
 }

pkg/domain/infra/tunnel/containers.go

@@ -722,6 +722,9 @@ func (ic *ContainerEngine) ContainerCp(ctx context.Context, source, dest string,
 func (ic *ContainerEngine) Shutdown(_ context.Context) {
 }
 
-func (ic *ContainerEngine) ContainerStats(ctx context.Context, namesOrIds []string, options entities.ContainerStatsOptions) error {
-	return errors.New("not implemented")
+func (ic *ContainerEngine) ContainerStats(ctx context.Context, namesOrIds []string, options entities.ContainerStatsOptions) (statsChan chan entities.ContainerStatsReport, err error) {
+	if options.Latest {
+		return nil, errors.New("latest is not supported for the remote client")
+	}
+	return containers.Stats(ic.ClientCxt, namesOrIds, &options.Stream)
 }

test/e2e/stats_test.go

@@ -1,4 +1,4 @@
-// +build !remote
+// +build
 
 package integration