package container
import (
"encoding/json"
"errors"
"fmt"
"io"
"strings"
"sync"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
"github.com/docker/go-units"
"golang.org/x/net/context"
)
type containerStats struct {
Name string
CPUPercentage float64
Memory float64 // On Windows this is the private working set
MemoryLimit float64 // Not used on Windows
MemoryPercentage float64 // Not used on Windows
NetworkRx float64
NetworkTx float64
BlockRead float64
BlockWrite float64
PidsCurrent uint64 // Not used on Windows
mu sync.Mutex
err error
}
type stats struct {
mu sync.Mutex
ostype string
cs []*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 *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 (s *containerStats) Collect(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 (s *containerStats) Display(w io.Writer) error {
s.mu.Lock()
defer s.mu.Unlock()
if daemonOSType == "windows" {
// NOTE: if you change this format, you must also change the err format below!
format := "%s\t%.2f%%\t%s\t%s / %s\t%s / %s\n"
if s.err != nil {
format = "%s\t%s\t%s\t%s / %s\t%s / %s\n"
errStr := "--"
fmt.Fprintf(w, format,
s.Name, errStr, errStr, errStr, errStr, errStr, errStr,
)
err := s.err
return err
}
fmt.Fprintf(w, format,
s.Name,
s.CPUPercentage,
units.BytesSize(s.Memory),
units.HumanSizeWithPrecision(s.NetworkRx, 3), units.HumanSizeWithPrecision(s.NetworkTx, 3),
units.HumanSizeWithPrecision(s.BlockRead, 3), units.HumanSizeWithPrecision(s.BlockWrite, 3))
} else {
// NOTE: if you change this format, you must also change the err format below!
format := "%s\t%.2f%%\t%s / %s\t%.2f%%\t%s / %s\t%s / %s\t%d\n"
if s.err != nil {
format = "%s\t%s\t%s / %s\t%s\t%s / %s\t%s / %s\t%s\n"
errStr := "--"
fmt.Fprintf(w, format,
s.Name, errStr, errStr, errStr, errStr, errStr, errStr, errStr, errStr, errStr,
)
err := s.err
return err
}
fmt.Fprintf(w, format,
s.Name,
s.CPUPercentage,
units.BytesSize(s.Memory), units.BytesSize(s.MemoryLimit),
s.MemoryPercentage,
units.HumanSizeWithPrecision(s.NetworkRx, 3), units.HumanSizeWithPrecision(s.NetworkTx, 3),
units.HumanSizeWithPrecision(s.BlockRead, 3), units.HumanSizeWithPrecision(s.BlockWrite, 3),
s.PidsCurrent)
}
return nil
}
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
}