From 8b40e44c395fb307cceb6f179ffe02030b316535 Mon Sep 17 00:00:00 2001
From: Alessandro Boch <aboch@docker.com>
Date: Wed, 1 Jul 2015 09:54:26 -0700
Subject: [PATCH] Stats API to retrieve nw stats from libnetwork - Container
 networking statistics are no longer   retrievable from libcontainer after the
 introduction   of libnetwork. This change adds the missing code   for docker
 daemon to retireve the nw stats from   Endpoint.

Signed-off-by: Alessandro Boch <aboch@docker.com>
---
 daemon/stats.go                          | 49 ++++++++++++++++++++++++
 integration-cli/docker_api_stats_test.go | 40 +++++++++++++++++++
 2 files changed, 89 insertions(+)

diff --git a/daemon/stats.go b/daemon/stats.go
index 646d7820b..a444c6027 100644
--- a/daemon/stats.go
+++ b/daemon/stats.go
@@ -6,6 +6,8 @@ import (
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/daemon/execdriver"
+	"github.com/docker/libcontainer"
+	"github.com/docker/libnetwork/sandbox"
 )
 
 type ContainerStatsConfig struct {
@@ -27,6 +29,10 @@ func (daemon *Daemon) ContainerStats(name string, config *ContainerStatsConfig)
 	var preCpuStats types.CpuStats
 	getStat := func(v interface{}) *types.Stats {
 		update := v.(*execdriver.ResourceStats)
+		// Retrieve the nw statistics from libnetwork and inject them in the Stats
+		if nwStats, err := daemon.getNetworkStats(name); err == nil {
+			update.Stats.Interfaces = nwStats
+		}
 		ss := convertStatsToAPITypes(update.Stats)
 		ss.PreCpuStats = preCpuStats
 		ss.MemoryStats.Limit = uint64(update.MemoryLimit)
@@ -67,3 +73,46 @@ func (daemon *Daemon) ContainerStats(name string, config *ContainerStatsConfig)
 		}
 	}
 }
+
+func (daemon *Daemon) getNetworkStats(name string) ([]*libcontainer.NetworkInterface, error) {
+	var list []*libcontainer.NetworkInterface
+
+	c, err := daemon.Get(name)
+	if err != nil {
+		return list, err
+	}
+
+	nw, err := daemon.netController.NetworkByID(c.NetworkSettings.NetworkID)
+	if err != nil {
+		return list, err
+	}
+	ep, err := nw.EndpointByID(c.NetworkSettings.EndpointID)
+	if err != nil {
+		return list, err
+	}
+
+	stats, err := ep.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 *sandbox.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
+}
diff --git a/integration-cli/docker_api_stats_test.go b/integration-cli/docker_api_stats_test.go
index 1d5d563c1..9f83f87e3 100644
--- a/integration-cli/docker_api_stats_test.go
+++ b/integration-cli/docker_api_stats_test.go
@@ -3,6 +3,8 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"os/exec"
+	"strconv"
 	"strings"
 	"time"
 
@@ -69,3 +71,41 @@ func (s *DockerSuite) TestStoppedContainerStatsGoroutines(c *check.C) {
 		}
 	}
 }
+
+func (s *DockerSuite) TestApiNetworkStats(c *check.C) {
+	// Run container for 30 secs
+	out, _ := dockerCmd(c, "run", "-d", "busybox", "top")
+	id := strings.TrimSpace(out)
+	err := waitRun(id)
+	c.Assert(err, check.IsNil)
+
+	// Retrieve the container address
+	contIP := findContainerIP(c, id)
+	numPings := 10
+
+	// Get the container networking stats before and after pinging the container
+	nwStatsPre := getNetworkStats(c, id)
+	_, err = exec.Command("ping", contIP, "-c", strconv.Itoa(numPings)).Output()
+	c.Assert(err, check.IsNil)
+	nwStatsPost := getNetworkStats(c, id)
+
+	// Verify the stats contain at least the expected number of packets (account for ARP)
+	expRxPkts := 1 + nwStatsPre.RxPackets + uint64(numPings)
+	expTxPkts := 1 + nwStatsPre.TxPackets + uint64(numPings)
+	c.Assert(nwStatsPost.TxPackets >= expTxPkts, check.Equals, true,
+		check.Commentf("Reported less TxPackets than expected. Expected >= %d. Found %d", expTxPkts, nwStatsPost.TxPackets))
+	c.Assert(nwStatsPost.RxPackets >= expRxPkts, check.Equals, true,
+		check.Commentf("Reported less Txbytes than expected. Expected >= %d. Found %d", expRxPkts, nwStatsPost.RxPackets))
+}
+
+func getNetworkStats(c *check.C, id string) types.Network {
+	var st *types.Stats
+
+	_, body, err := sockRequestRaw("GET", fmt.Sprintf("/containers/%s/stats?stream=false", id), nil, "")
+	c.Assert(err, check.IsNil)
+
+	err = json.NewDecoder(body).Decode(&st)
+	c.Assert(err, check.IsNil)
+
+	return st.Network
+}