package container import ( "encoding/json" "errors" "io" "strings" "sync" "time" "github.com/Sirupsen/logrus" "github.com/docker/docker/api/types" "github.com/docker/docker/cli/command/formatter" "github.com/docker/docker/client" "golang.org/x/net/context" ) type stats struct { ostype string mu sync.RWMutex cs []*formatter.ContainerStats } // daemonOSType is set once we have at least one stat for a container // from the daemon. It is used to ensure we print the right header based // on the daemon platform. var daemonOSType string func (s *stats) add(cs *formatter.ContainerStats) bool { s.mu.Lock() defer s.mu.Unlock() if _, exists := s.isKnownContainer(cs.Name); !exists { s.cs = append(s.cs, cs) return true } return false } func (s *stats) remove(id string) { s.mu.Lock() if i, exists := s.isKnownContainer(id); exists { s.cs = append(s.cs[:i], s.cs[i+1:]...) } s.mu.Unlock() } func (s *stats) isKnownContainer(cid string) (int, bool) { for i, c := range s.cs { if c.Name == cid { return i, true } } return -1, false } func collect(s *formatter.ContainerStats, ctx context.Context, cli client.APIClient, streamStats bool, waitFirst *sync.WaitGroup) { logrus.Debugf("collecting stats for %s", s.Name) var ( getFirst bool previousCPU uint64 previousSystem uint64 u = make(chan error, 1) ) defer func() { // if error happens and we get nothing of stats, release wait group whatever if !getFirst { getFirst = true waitFirst.Done() } }() response, err := cli.ContainerStats(ctx, s.Name, streamStats) if err != nil { s.Mu.Lock() s.Err = err s.Mu.Unlock() return } defer response.Body.Close() dec := json.NewDecoder(response.Body) go func() { for { var ( v *types.StatsJSON memPercent = 0.0 cpuPercent = 0.0 blkRead, blkWrite uint64 // Only used on Linux mem = 0.0 ) if err := dec.Decode(&v); err != nil { dec = json.NewDecoder(io.MultiReader(dec.Buffered(), response.Body)) u <- err if err == io.EOF { break } time.Sleep(100 * time.Millisecond) continue } daemonOSType = response.OSType if daemonOSType != "windows" { // MemoryStats.Limit will never be 0 unless the container is not running and we haven't // got any data from cgroup if v.MemoryStats.Limit != 0 { memPercent = float64(v.MemoryStats.Usage) / float64(v.MemoryStats.Limit) * 100.0 } previousCPU = v.PreCPUStats.CPUUsage.TotalUsage previousSystem = v.PreCPUStats.SystemUsage cpuPercent = calculateCPUPercentUnix(previousCPU, previousSystem, v) blkRead, blkWrite = calculateBlockIO(v.BlkioStats) mem = float64(v.MemoryStats.Usage) } else { cpuPercent = calculateCPUPercentWindows(v) blkRead = v.StorageStats.ReadSizeBytes blkWrite = v.StorageStats.WriteSizeBytes mem = float64(v.MemoryStats.PrivateWorkingSet) } s.Mu.Lock() s.CPUPercentage = cpuPercent s.Memory = mem s.NetworkRx, s.NetworkTx = calculateNetwork(v.Networks) s.BlockRead = float64(blkRead) s.BlockWrite = float64(blkWrite) if daemonOSType != "windows" { s.MemoryLimit = float64(v.MemoryStats.Limit) s.MemoryPercentage = memPercent s.PidsCurrent = v.PidsStats.Current } s.Mu.Unlock() u <- nil if !streamStats { return } } }() for { select { case <-time.After(2 * time.Second): // zero out the values if we have not received an update within // the specified duration. s.Mu.Lock() s.CPUPercentage = 0 s.Memory = 0 s.MemoryPercentage = 0 s.MemoryLimit = 0 s.NetworkRx = 0 s.NetworkTx = 0 s.BlockRead = 0 s.BlockWrite = 0 s.PidsCurrent = 0 s.Err = errors.New("timeout waiting for stats") s.Mu.Unlock() // if this is the first stat you get, release WaitGroup if !getFirst { getFirst = true waitFirst.Done() } case err := <-u: if err != nil { s.Mu.Lock() s.Err = err s.Mu.Unlock() continue } s.Err = nil // if this is the first stat you get, release WaitGroup if !getFirst { getFirst = true waitFirst.Done() } } if !streamStats { return } } } func calculateCPUPercentUnix(previousCPU, previousSystem uint64, v *types.StatsJSON) float64 { var ( cpuPercent = 0.0 // calculate the change for the cpu usage of the container in between readings cpuDelta = float64(v.CPUStats.CPUUsage.TotalUsage) - float64(previousCPU) // calculate the change for the entire system between readings systemDelta = float64(v.CPUStats.SystemUsage) - float64(previousSystem) ) if systemDelta > 0.0 && cpuDelta > 0.0 { cpuPercent = (cpuDelta / systemDelta) * float64(len(v.CPUStats.CPUUsage.PercpuUsage)) * 100.0 } return cpuPercent } func calculateCPUPercentWindows(v *types.StatsJSON) float64 { // Max number of 100ns intervals between the previous time read and now possIntervals := uint64(v.Read.Sub(v.PreRead).Nanoseconds()) // Start with number of ns intervals possIntervals /= 100 // Convert to number of 100ns intervals possIntervals *= uint64(v.NumProcs) // Multiple by the number of processors // Intervals used intervalsUsed := v.CPUStats.CPUUsage.TotalUsage - v.PreCPUStats.CPUUsage.TotalUsage // Percentage avoiding divide-by-zero if possIntervals > 0 { return float64(intervalsUsed) / float64(possIntervals) * 100.0 } return 0.00 } func calculateBlockIO(blkio types.BlkioStats) (blkRead uint64, blkWrite uint64) { for _, bioEntry := range blkio.IoServiceBytesRecursive { switch strings.ToLower(bioEntry.Op) { case "read": blkRead = blkRead + bioEntry.Value case "write": blkWrite = blkWrite + bioEntry.Value } } return } func calculateNetwork(network map[string]types.NetworkStats) (float64, float64) { var rx, tx float64 for _, v := range network { rx += float64(v.RxBytes) tx += float64(v.TxBytes) } return rx, tx }