package daemon import ( "encoding/json" "io" "github.com/docker/docker/api/types" "github.com/docker/docker/context" "github.com/docker/docker/daemon/execdriver" "github.com/docker/docker/pkg/version" "github.com/docker/libnetwork/osl" "github.com/opencontainers/runc/libcontainer" ) // ContainerStatsConfig holds information for configuring the runtime // behavior of a daemon.ContainerStats() call. type ContainerStatsConfig struct { Stream bool OutStream io.Writer Stop <-chan bool Version version.Version } // ContainerStats writes information about the container to the stream // given in the config object. func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, config *ContainerStatsConfig) error { container, err := daemon.Get(ctx, 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{}) } updates, err := daemon.subscribeToContainerStats(container) if err != nil { return err } if config.Stream { // Write an empty chunk of data. // This is to ensure that the HTTP status code is sent immediately, // even if the container has not yet produced any data. config.OutStream.Write(nil) } var preCPUStats types.CPUStats getStatJSON := func(v interface{}) *types.StatsJSON { update := v.(*execdriver.ResourceStats) // Retrieve the nw statistics from libnetwork and inject them in the Stats if nwStats, err := daemon.getNetworkStats(container); err == nil { update.Stats.Interfaces = nwStats } 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(config.OutStream) defer daemon.unsubscribeToContainerStats(container, updates) noStreamFirstFrame := true for { select { case v, ok := <-updates: if !ok { return nil } statsJSON := getStatJSON(v) if config.Version.LessThan("1.21") { var ( rxBytes uint64 rxPackets uint64 rxErrors uint64 rxDropped uint64 txBytes uint64 txPackets uint64 txErrors uint64 txDropped uint64 ) for _, v := range statsJSON.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 } statsJSONPre121 := &types.StatsJSONPre121{ Stats: statsJSON.Stats, Network: types.NetworkStats{ RxBytes: rxBytes, RxPackets: rxPackets, RxErrors: rxErrors, RxDropped: rxDropped, TxBytes: txBytes, TxPackets: txPackets, TxErrors: txErrors, TxDropped: txDropped, }, } if !config.Stream && noStreamFirstFrame { // prime the cpu stats so they aren't 0 in the final output noStreamFirstFrame = false continue } if err := enc.Encode(statsJSONPre121); err != nil { return err } if !config.Stream { return nil } } 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 } } } func (daemon *Daemon) getNetworkStats(c *Container) ([]*libcontainer.NetworkInterface, error) { var list []*libcontainer.NetworkInterface sb, err := daemon.netController.SandboxByID(c.NetworkSettings.SandboxID) if err != nil { return list, err } stats, err := sb.Statistics() if err != nil { return list, err } // Convert libnetwork nw stats into libcontainer nw stats for ifName, ifStats := range stats { list = append(list, convertLnNetworkStats(ifName, ifStats)) } return list, nil } func convertLnNetworkStats(name string, stats *osl.InterfaceStatistics) *libcontainer.NetworkInterface { n := &libcontainer.NetworkInterface{Name: name} n.RxBytes = stats.RxBytes n.RxPackets = stats.RxPackets n.RxErrors = stats.RxErrors n.RxDropped = stats.RxDropped n.TxBytes = stats.TxBytes n.TxPackets = stats.TxPackets n.TxErrors = stats.TxErrors n.TxDropped = stats.TxDropped return n }