implements pernic of NetIOCounters.

README.rst

@@ -138,7 +138,7 @@ swap_memory          x           x         x            x
 disk_partitions      x           x         x            x       x
 disk_io_counters     x           x
 disk_usage           x           x         x            x       x
-net_io_counters      x           x         x            x       x
+net_io_counters      x           x         x            b       x
 boot_time            x           x         x            x       b
 users                x           x         x            x       x
 pids                 x           x         x            x       x
@@ -252,7 +252,8 @@ I have been influenced by the following great works:
 - goprocinfo: https://github.com/c9s/goprocinfo
 - go-ps: https://github.com/mitchellh/go-ps
 - ohai: https://github.com/opscode/ohai/
-
+- bosun: https://github.com/bosun-monitor/bosun/tree/master/cmd/scollector/collectors
+- mackerel: https://github.com/mackerelio/mackerel-agent/tree/master/metrics
 
 How to Contribute
 ---------------------------

common/common.go

@@ -1,5 +1,5 @@
 //
-// common is a port of psutil(http://pythonhosted.org/psutil/).
+// gopsutil is a port of psutil(http://pythonhosted.org/psutil/).
 // This covers these architectures.
 //  - linux (amd64, arm)
 //  - freebsd (amd64)

net/net.go

@@ -117,3 +117,21 @@ func NetInterfaces() ([]NetInterfaceStat, error) {
 
 	return ret, nil
 }
+
+func getNetIOCountersAll(n []NetIOCountersStat) ([]NetIOCountersStat, error) {
+	r := NetIOCountersStat{
+		Name: "all",
+	}
+	for _, nic := range n {
+		r.BytesRecv += nic.BytesRecv
+		r.PacketsRecv += nic.PacketsRecv
+		r.Errin += nic.Errin
+		r.Dropin += nic.Dropin
+		r.BytesSent += nic.BytesSent
+		r.PacketsSent += nic.PacketsSent
+		r.Errout += nic.Errout
+		r.Dropout += nic.Dropout
+	}
+
+	return []NetIOCountersStat{r}, nil
+}

net/net_darwin.go

@@ -57,5 +57,9 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 		ret = append(ret, n)
 	}
 
+	if pernic == false {
+		return getNetIOCountersAll(ret)
+	}
+
 	return ret, nil
 }

net/net_freebsd.go

@@ -66,5 +66,9 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 		ret = append(ret, n)
 	}
 
+	if pernic == false {
+		return getNetIOCountersAll(ret)
+	}
+
 	return ret, nil
 }

net/net_linux.go

@@ -9,6 +9,11 @@ import (
 	common "github.com/shirou/gopsutil/common"
 )
 
+// NetIOCounters returnes network I/O statistics for every network
+// interface installed on the system.  If pernic argument is false,
+// return only sum of all information (which name is 'all'). If true,
+// every network interface installed on the system is returned
+// separately.
 func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 	filename := "/proc/net/dev"
 	lines, err := common.ReadLines(filename)
@@ -77,5 +82,10 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 		}
 		ret = append(ret, nic)
 	}
+
+	if pernic == false {
+		return getNetIOCountersAll(ret)
+	}
+
 	return ret, nil
 }

net/net_test.go

@@ -38,7 +38,28 @@ func TestNetConnectionStatString(t *testing.T) {
 
 }
 
-func TestNetIOCounters(t *testing.T) {
+func TestNetIOCountersAll(t *testing.T) {
+	v, err := NetIOCounters(false)
+	per, err := NetIOCounters(true)
+	if err != nil {
+		t.Errorf("Could not get NetIOCounters: %v", err)
+	}
+	if len(v) != 1 {
+		t.Errorf("Could not get NetIOCounters: %v", v)
+	}
+	if v[0].Name != "all" {
+		t.Errorf("Invalid NetIOCounters: %v", v)
+	}
+	var pr uint64
+	for _, p := range per {
+		pr += p.PacketsRecv
+	}
+	if v[0].PacketsRecv != pr {
+		t.Errorf("invalid sum value: %v, %v", v[0].PacketsRecv, pr)
+	}
+}
+
+func TestNetIOCountersPerNic(t *testing.T) {
 	v, err := NetIOCounters(true)
 	if err != nil {
 		t.Errorf("Could not get NetIOCounters: %v", err)
@@ -53,6 +74,38 @@ func TestNetIOCounters(t *testing.T) {
 	}
 }
 
+func Test_getNetIOCountersAll(t *testing.T) {
+	n := []NetIOCountersStat{
+		NetIOCountersStat{
+			Name:        "a",
+			BytesRecv:   10,
+			PacketsRecv: 10,
+		},
+		NetIOCountersStat{
+			Name:        "b",
+			BytesRecv:   10,
+			PacketsRecv: 10,
+			Errin:       10,
+		},
+	}
+	ret, err := getNetIOCountersAll(n)
+	if err != nil {
+		t.Error(err)
+	}
+	if len(ret) != 1 {
+		t.Errorf("invalid return count")
+	}
+	if ret[0].Name != "all" {
+		t.Errorf("invalid return name")
+	}
+	if ret[0].BytesRecv != 20 {
+		t.Errorf("invalid count bytesrecv")
+	}
+	if ret[0].Errin != 10 {
+		t.Errorf("invalid count errin")
+	}
+}
+
 func TestNetInterfaces(t *testing.T) {
 	v, err := NetInterfaces()
 	if err != nil {

net/net_windows.go

@@ -66,6 +66,10 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 			ret = append(ret, c)
 		}
 	}
+
+	if pernic == false {
+		return getNetIOCountersAll(ret)
+	}
 	return ret, nil
 }