github.com/kim0/docker@v0.6.2-0.20161130212042-4addda3f07e7/daemon/stats.go (about)

     1  package daemon
     2  
     3  import (
     4  	"encoding/json"
     5  	"errors"
     6  	"runtime"
     7  	"time"
     8  
     9  	"golang.org/x/net/context"
    10  
    11  	"github.com/docker/docker/api/types"
    12  	"github.com/docker/docker/api/types/backend"
    13  	"github.com/docker/docker/api/types/versions"
    14  	"github.com/docker/docker/api/types/versions/v1p20"
    15  	"github.com/docker/docker/container"
    16  	"github.com/docker/docker/pkg/ioutils"
    17  )
    18  
    19  // ContainerStats writes information about the container to the stream
    20  // given in the config object.
    21  func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, config *backend.ContainerStatsConfig) error {
    22  	// Remote API version (used for backwards compatibility)
    23  	apiVersion := config.Version
    24  
    25  	container, err := daemon.GetContainer(prefixOrName)
    26  	if err != nil {
    27  		return err
    28  	}
    29  
    30  	// If the container is not running and requires no stream, return an empty stats.
    31  	if !container.IsRunning() && !config.Stream {
    32  		return json.NewEncoder(config.OutStream).Encode(&types.Stats{})
    33  	}
    34  
    35  	outStream := config.OutStream
    36  	if config.Stream {
    37  		wf := ioutils.NewWriteFlusher(outStream)
    38  		defer wf.Close()
    39  		wf.Flush()
    40  		outStream = wf
    41  	}
    42  
    43  	var preCPUStats types.CPUStats
    44  	var preRead time.Time
    45  	getStatJSON := func(v interface{}) *types.StatsJSON {
    46  		ss := v.(types.StatsJSON)
    47  		ss.PreCPUStats = preCPUStats
    48  		ss.PreRead = preRead
    49  		preCPUStats = ss.CPUStats
    50  		preRead = ss.Read
    51  		return &ss
    52  	}
    53  
    54  	enc := json.NewEncoder(outStream)
    55  
    56  	updates := daemon.subscribeToContainerStats(container)
    57  	defer daemon.unsubscribeToContainerStats(container, updates)
    58  
    59  	noStreamFirstFrame := true
    60  	for {
    61  		select {
    62  		case v, ok := <-updates:
    63  			if !ok {
    64  				return nil
    65  			}
    66  
    67  			var statsJSON interface{}
    68  			statsJSONPost120 := getStatJSON(v)
    69  			if versions.LessThan(apiVersion, "1.21") {
    70  				if runtime.GOOS == "windows" {
    71  					return errors.New("API versions pre v1.21 do not support stats on Windows")
    72  				}
    73  				var (
    74  					rxBytes   uint64
    75  					rxPackets uint64
    76  					rxErrors  uint64
    77  					rxDropped uint64
    78  					txBytes   uint64
    79  					txPackets uint64
    80  					txErrors  uint64
    81  					txDropped uint64
    82  				)
    83  				for _, v := range statsJSONPost120.Networks {
    84  					rxBytes += v.RxBytes
    85  					rxPackets += v.RxPackets
    86  					rxErrors += v.RxErrors
    87  					rxDropped += v.RxDropped
    88  					txBytes += v.TxBytes
    89  					txPackets += v.TxPackets
    90  					txErrors += v.TxErrors
    91  					txDropped += v.TxDropped
    92  				}
    93  				statsJSON = &v1p20.StatsJSON{
    94  					Stats: statsJSONPost120.Stats,
    95  					Network: types.NetworkStats{
    96  						RxBytes:   rxBytes,
    97  						RxPackets: rxPackets,
    98  						RxErrors:  rxErrors,
    99  						RxDropped: rxDropped,
   100  						TxBytes:   txBytes,
   101  						TxPackets: txPackets,
   102  						TxErrors:  txErrors,
   103  						TxDropped: txDropped,
   104  					},
   105  				}
   106  			} else {
   107  				statsJSON = statsJSONPost120
   108  			}
   109  
   110  			if !config.Stream && noStreamFirstFrame {
   111  				// prime the cpu stats so they aren't 0 in the final output
   112  				noStreamFirstFrame = false
   113  				continue
   114  			}
   115  
   116  			if err := enc.Encode(statsJSON); err != nil {
   117  				return err
   118  			}
   119  
   120  			if !config.Stream {
   121  				return nil
   122  			}
   123  		case <-ctx.Done():
   124  			return nil
   125  		}
   126  	}
   127  }
   128  
   129  func (daemon *Daemon) subscribeToContainerStats(c *container.Container) chan interface{} {
   130  	return daemon.statsCollector.collect(c)
   131  }
   132  
   133  func (daemon *Daemon) unsubscribeToContainerStats(c *container.Container, ch chan interface{}) {
   134  	daemon.statsCollector.unsubscribe(c, ch)
   135  }
   136  
   137  // GetContainerStats collects all the stats published by a container
   138  func (daemon *Daemon) GetContainerStats(container *container.Container) (*types.StatsJSON, error) {
   139  	stats, err := daemon.stats(container)
   140  	if err != nil {
   141  		return nil, err
   142  	}
   143  
   144  	// We already have the network stats on Windows directly from HCS.
   145  	if !container.Config.NetworkDisabled && runtime.GOOS != "windows" {
   146  		if stats.Networks, err = daemon.getNetworkStats(container); err != nil {
   147  			return nil, err
   148  		}
   149  	}
   150  
   151  	return stats, nil
   152  }