package daemon import ( "encoding/json" "errors" "runtime" "github.com/docker/docker/api/types/backend" "github.com/docker/docker/daemon/execdriver" "github.com/docker/docker/pkg/ioutils" "github.com/docker/docker/pkg/version" "github.com/docker/engine-api/types" "github.com/docker/engine-api/types/versions/v1p20" ) // ContainerStats writes information about the container to the stream // given in the config object. func (daemon *Daemon) ContainerStats(prefixOrName string, config *backend.ContainerStatsConfig) error { if runtime.GOOS == "windows" { return errors.New("Windows does not support stats") } // Remote API version (used for backwards compatibility) apiVersion := version.Version(config.Version) container, err := daemon.GetContainer(prefixOrName) if err != nil { return err } // If the container is not running and requires no stream, return an empty stats. if !container.IsRunning() && !config.Stream { return json.NewEncoder(config.OutStream).Encode(&types.Stats{}) } outStream := config.OutStream if config.Stream { wf := ioutils.NewWriteFlusher(outStream) defer wf.Close() wf.Flush() outStream = wf } var preCPUStats types.CPUStats getStatJSON := func(v interface{}) *types.StatsJSON { update := v.(*execdriver.ResourceStats) ss := convertStatsToAPITypes(update.Stats) ss.PreCPUStats = preCPUStats ss.MemoryStats.Limit = uint64(update.MemoryLimit) ss.Read = update.Read ss.CPUStats.SystemUsage = update.SystemUsage preCPUStats = ss.CPUStats return ss } enc := json.NewEncoder(outStream) updates := daemon.subscribeToContainerStats(container) defer daemon.unsubscribeToContainerStats(container, updates) noStreamFirstFrame := true for { select { case v, ok := <-updates: if !ok { return nil } var statsJSON interface{} statsJSONPost120 := getStatJSON(v) if apiVersion.LessThan("1.21") { var ( rxBytes uint64 rxPackets uint64 rxErrors uint64 rxDropped uint64 txBytes uint64 txPackets uint64 txErrors uint64 txDropped uint64 ) for _, v := range statsJSONPost120.Networks { rxBytes += v.RxBytes rxPackets += v.RxPackets rxErrors += v.RxErrors rxDropped += v.RxDropped txBytes += v.TxBytes txPackets += v.TxPackets txErrors += v.TxErrors txDropped += v.TxDropped } statsJSON = &v1p20.StatsJSON{ Stats: statsJSONPost120.Stats, Network: types.NetworkStats{ RxBytes: rxBytes, RxPackets: rxPackets, RxErrors: rxErrors, RxDropped: rxDropped, TxBytes: txBytes, TxPackets: txPackets, TxErrors: txErrors, TxDropped: txDropped, }, } } else { statsJSON = statsJSONPost120 } if !config.Stream && noStreamFirstFrame { // prime the cpu stats so they aren't 0 in the final output noStreamFirstFrame = false continue } if err := enc.Encode(statsJSON); err != nil { return err } if !config.Stream { return nil } case <-config.Stop: return nil } } }