Refactor the statistics of network in docker stats

For now docker stats will sum the rxbytes, txbytes, etc. of all
the interfaces.

It is OK for the output of CLI `docker stats` but not good for
the API response, especially when the container is in sereval
subnets.

It's better to leave these origianl data to user.

Signed-off-by: Hu Keping <hukeping@huawei.com>

api/client/stats.go

@@ -56,7 +56,7 @@ func (s *containerStats) Collect(cli *DockerCli, streamStats bool) {
 	)
 	go func() {
 		for {
-			var v *types.Stats
+			var v *types.StatsJSON
 			if err := dec.Decode(&v); err != nil {
 				u <- err
 				return
@@ -80,8 +80,7 @@ func (s *containerStats) Collect(cli *DockerCli, streamStats bool) {
 			s.Memory = float64(v.MemoryStats.Usage)
 			s.MemoryLimit = float64(v.MemoryStats.Limit)
 			s.MemoryPercentage = memPercent
-			s.NetworkRx = float64(v.Network.RxBytes)
+			s.NetworkRx, s.NetworkTx = calculateNetwork(v.Networks)
-			s.NetworkTx = float64(v.Network.TxBytes)
 			s.BlockRead = float64(blkRead)
 			s.BlockWrite = float64(blkWrite)
 			s.mu.Unlock()
@@ -198,7 +197,7 @@ func (cli *DockerCli) CmdStats(args ...string) error {
 	return nil
 }
 
-func calculateCPUPercent(previousCPU, previousSystem uint64, v *types.Stats) float64 {
+func calculateCPUPercent(previousCPU, previousSystem uint64, v *types.StatsJSON) float64 {
 	var (
 		cpuPercent = 0.0
 		// calculate the change for the cpu usage of the container in between readings
@@ -224,3 +223,13 @@ func calculateBlockIO(blkio types.BlkioStats) (blkRead uint64, blkWrite uint64)
 	}
 	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
+}

api/server/container.go

@@ -17,6 +17,7 @@ import (
 	"github.com/docker/docker/daemon"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/signal"
+	"github.com/docker/docker/pkg/version"
 	"github.com/docker/docker/runconfig"
 )
 
@@ -81,10 +82,12 @@ func (s *Server) getContainersStats(ctx context.Context, w http.ResponseWriter,
 		closeNotifier = notifier.CloseNotify()
 	}
 
+	version, _ := ctx.Value("api-version").(version.Version)
 	config := &daemon.ContainerStatsConfig{
 		Stream:    stream,
 		OutStream: out,
 		Stop:      closeNotifier,
+		Version:   version,
 	}
 
 	return s.daemon.ContainerStats(container, config)

api/types/stats.go

@@ -90,9 +90,24 @@ type NetworkStats struct {
 // Stats is Ultimate struct aggregating all types of stats of one container
 type Stats struct {
 	Read        time.Time   `json:"read"`
-	Network     NetworkStats `json:"network,omitempty"`
 	PreCPUStats CPUStats    `json:"precpu_stats,omitempty"`
 	CPUStats    CPUStats    `json:"cpu_stats,omitempty"`
 	MemoryStats MemoryStats `json:"memory_stats,omitempty"`
 	BlkioStats  BlkioStats  `json:"blkio_stats,omitempty"`
 }
+
+// StatsJSONPre121 is a backcompatibility struct along with ContainerConfig
+type StatsJSONPre121 struct {
+	Stats
+
+	// Network is for fallback stats where API Version < 1.21
+	Network NetworkStats `json:"network,omitempty"`
+}
+
+// StatsJSON is newly used Networks
+type StatsJSON struct {
+	Stats
+
+	// Networks request version >=1.21
+	Networks map[string]NetworkStats `json:"networks,omitempty"`
+}

daemon/stats.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/daemon/execdriver"
+	"github.com/docker/docker/pkg/version"
 	"github.com/docker/libnetwork/osl"
 	"github.com/opencontainers/runc/libcontainer"
 )
@@ -16,6 +17,7 @@ type ContainerStatsConfig struct {
 	Stream    bool
 	OutStream io.Writer
 	Stop      <-chan bool
+	Version   version.Version
 }
 
 // ContainerStats writes information about the container to the stream
@@ -31,7 +33,7 @@ func (daemon *Daemon) ContainerStats(container *Container, config *ContainerStat
 	}
 
 	var preCPUStats types.CPUStats
-	getStat := func(v interface{}) *types.Stats {
+	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 {
@@ -58,14 +60,64 @@ func (daemon *Daemon) ContainerStats(container *Container, config *ContainerStat
 				return nil
 			}
 
-			s := getStat(v)
+			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(s); err != nil {
+				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
 			}
 

daemon/stats_freebsd.go

@@ -7,8 +7,8 @@ import (
 
 // convertStatsToAPITypes converts the libcontainer.Stats to the api specific
 // structs. This is done to preserve API compatibility and versioning.
-func convertStatsToAPITypes(ls *libcontainer.Stats) *types.Stats {
+func convertStatsToAPITypes(ls *libcontainer.Stats) *types.StatsJSON {
 	// TODO FreeBSD. Refactor accordingly to fill in stats.
-	s := &types.Stats{}
+	s := &types.StatsJSON{}
 	return s
 }

daemon/stats_linux.go

@@ -8,19 +8,23 @@ import (
 
 // convertStatsToAPITypes converts the libcontainer.Stats to the api specific
 // structs. This is done to preserve API compatibility and versioning.
-func convertStatsToAPITypes(ls *libcontainer.Stats) *types.Stats {
+func convertStatsToAPITypes(ls *libcontainer.Stats) *types.StatsJSON {
-	s := &types.Stats{}
+	s := &types.StatsJSON{}
 	if ls.Interfaces != nil {
-		s.Network = types.NetworkStats{}
+		s.Networks = make(map[string]types.NetworkStats)
 		for _, iface := range ls.Interfaces {
-			s.Network.RxBytes += iface.RxBytes
+			// For API Version >= 1.21, the original data of network will
-			s.Network.RxPackets += iface.RxPackets
+			// be returned.
-			s.Network.RxErrors += iface.RxErrors
+			s.Networks[iface.Name] = types.NetworkStats{
-			s.Network.RxDropped += iface.RxDropped
+				RxBytes:   iface.RxBytes,
-			s.Network.TxBytes += iface.TxBytes
+				RxPackets: iface.RxPackets,
-			s.Network.TxPackets += iface.TxPackets
+				RxErrors:  iface.RxErrors,
-			s.Network.TxErrors += iface.TxErrors
+				RxDropped: iface.RxDropped,
-			s.Network.TxDropped += iface.TxDropped
+				TxBytes:   iface.TxBytes,
+				TxPackets: iface.TxPackets,
+				TxErrors:  iface.TxErrors,
+				TxDropped: iface.TxDropped,
+			}
 		}
 	}
 

daemon/stats_windows.go

@@ -7,8 +7,8 @@ import (
 
 // convertStatsToAPITypes converts the libcontainer.Stats to the api specific
 // structs. This is done to preserve API compatibility and versioning.
-func convertStatsToAPITypes(ls *libcontainer.Stats) *types.Stats {
+func convertStatsToAPITypes(ls *libcontainer.Stats) *types.StatsJSON {
 	// TODO Windows. Refactor accordingly to fill in stats.
-	s := &types.Stats{}
+	s := &types.StatsJSON{}
 	return s
 }

docs/reference/api/docker_remote_api.md

@@ -83,6 +83,7 @@ This section lists each version from latest to oldest.  Each listing includes a
 * `VolumeDriver` has been moved from config to hostConfig to make the configuration portable.
 * `GET /images/(name)/json` now returns information about tags of the image.
 * The `config` option now accepts the field `StopSignal`, which specifies the signal to use to kill a container.
+* `GET /containers/(id)/stats` will return networking information respectively for each interface.
 
 
 ### v1.20 API changes

docs/reference/api/docker_remote_api_v1.21.md

@@ -631,15 +631,27 @@ This endpoint returns a live stream of a container's resource usage statistics.
 
       {
          "read" : "2015-01-08T22:57:31.547920715Z",
-         "network" : {
+         "network": {
-            "rx_dropped" : 0,
+                 "eth0": {
-            "rx_bytes" : 648,
+                     "rx_bytes": 5338,
-            "rx_errors" : 0,
+                     "rx_dropped": 0,
-            "tx_packets" : 8,
+                     "rx_errors": 0,
-            "tx_dropped" : 0,
+                     "rx_packets": 36,
-            "rx_packets" : 8,
+                     "tx_bytes": 648,
-            "tx_errors" : 0,
+                     "tx_dropped": 0,
-            "tx_bytes" : 648
+                     "tx_errors": 0,
+                     "tx_packets": 8
+                 },
+                 "eth5": {
+                     "rx_bytes": 4641,
+                     "rx_dropped": 0,
+                     "rx_errors": 0,
+                     "rx_packets": 26,
+                     "tx_bytes": 690,
+                     "tx_dropped": 0,
+                     "tx_errors": 0,
+                     "tx_packets": 9
+                 }
          },
          "memory_stats" : {
             "stats" : {

integration-cli/docker_api_stats_test.go

@@ -87,8 +87,18 @@ func (s *DockerSuite) TestApiNetworkStats(c *check.C) {
 	contIP := findContainerIP(c, id)
 	numPings := 10
 
+	var preRxPackets uint64
+	var preTxPackets uint64
+	var postRxPackets uint64
+	var postTxPackets uint64
+
 	// Get the container networking stats before and after pinging the container
 	nwStatsPre := getNetworkStats(c, id)
+	for _, v := range nwStatsPre {
+		preRxPackets += v.RxPackets
+		preTxPackets += v.TxPackets
+	}
+
 	countParam := "-c"
 	if runtime.GOOS == "windows" {
 		countParam = "-n" // Ping count parameter is -n on Windows
@@ -97,18 +107,22 @@ func (s *DockerSuite) TestApiNetworkStats(c *check.C) {
 	pingouts := string(pingout[:])
 	c.Assert(err, check.IsNil)
 	nwStatsPost := getNetworkStats(c, id)
+	for _, v := range nwStatsPost {
+		postRxPackets += v.RxPackets
+		postTxPackets += v.TxPackets
+	}
 
 	// Verify the stats contain at least the expected number of packets (account for ARP)
-	expRxPkts := 1 + nwStatsPre.RxPackets + uint64(numPings)
+	expRxPkts := 1 + preRxPackets + uint64(numPings)
-	expTxPkts := 1 + nwStatsPre.TxPackets + uint64(numPings)
+	expTxPkts := 1 + preTxPackets + uint64(numPings)
-	c.Assert(nwStatsPost.TxPackets >= expTxPkts, check.Equals, true,
+	c.Assert(postTxPackets >= expTxPkts, check.Equals, true,
-		check.Commentf("Reported less TxPackets than expected. Expected >= %d. Found %d. %s", expTxPkts, nwStatsPost.TxPackets, pingouts))
+		check.Commentf("Reported less TxPackets than expected. Expected >= %d. Found %d. %s", expTxPkts, postTxPackets, pingouts))
-	c.Assert(nwStatsPost.RxPackets >= expRxPkts, check.Equals, true,
+	c.Assert(postRxPackets >= expRxPkts, check.Equals, true,
-		check.Commentf("Reported less Txbytes than expected. Expected >= %d. Found %d. %s", expRxPkts, nwStatsPost.RxPackets, pingouts))
+		check.Commentf("Reported less Txbytes than expected. Expected >= %d. Found %d. %s", expRxPkts, postRxPackets, pingouts))
 }
 
-func getNetworkStats(c *check.C, id string) types.NetworkStats {
+func getNetworkStats(c *check.C, id string) map[string]types.NetworkStats {
-	var st *types.Stats
+	var st *types.StatsJSON
 
 	_, body, err := sockRequestRaw("GET", fmt.Sprintf("/containers/%s/stats?stream=false", id), nil, "")
 	c.Assert(err, check.IsNil)
@@ -117,5 +131,5 @@ func getNetworkStats(c *check.C, id string) types.NetworkStats {
 	c.Assert(err, check.IsNil)
 	body.Close()
 
-	return st.Network
+	return st.Networks
 }