Add wireless input plugin (influxdata#3847)

plugins/inputs/all/all.go

@@ -135,6 +135,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/webhooks"
 	_ "github.com/influxdata/telegraf/plugins/inputs/win_perf_counters"
 	_ "github.com/influxdata/telegraf/plugins/inputs/win_services"
+	_ "github.com/influxdata/telegraf/plugins/inputs/wireless"
 	_ "github.com/influxdata/telegraf/plugins/inputs/x509_cert"
 	_ "github.com/influxdata/telegraf/plugins/inputs/zfs"
 	_ "github.com/influxdata/telegraf/plugins/inputs/zipkin"

plugins/inputs/wireless/README.md

@@ -0,0 +1,38 @@
+# Wireless Input Plugin
+
+The wireless plugin gathers metrics about wireless link quality by reading the `/proc/net/wireless` file. This plugin currently supports linux only.
+
+### Configuration:
+
+```toml
+# Monitor wifi signal strength and quality
+[[inputs.wireless]]
+  ## Sets 'proc' directory path
+  ## If not specified, then default is /proc
+  # host_proc = "/proc"
+```
+
+### Metrics:
+
+- metric
+  - tags:
+    - interface (wireless interface)
+  - fields:
+    - status (int64, gauge) - Its current state. This is a device dependent information
+    - link (int64, percentage, gauge) - general quality of the reception
+    - level (int64, dBm, gauge) - signal strength at the receiver
+    - noise (int64, dBm, gauge) - silence level (no packet) at the receiver
+    - nwid (int64, packets, counter) - number of discarded packets due to invalid network id
+    - crypt (int64, packets, counter) - number of packet unable to decrypt
+    - frag (int64, packets, counter) - fragmented packets
+    - retry (int64, packets, counter) - cumulative retry counts
+    - misc (int64, packets, counter) - dropped for un-specified reason
+    - missed_beacon (int64, packets, counter) - missed beacon packets
+
+### Example Output:
+
+This section shows example output in Line Protocol format.
+
+```
+wireless,host=example.localdomain,interface=wlan0 misc=0i,frag=0i,link=60i,level=-50i,noise=-256i,nwid=0i,crypt=0i,retry=1525i,missed_beacon=0i,status=0i 1519843022000000000
+```

plugins/inputs/wireless/wireless.go

@@ -0,0 +1,3 @@
+// +build !linux
+
+package wireless

plugins/inputs/wireless/wireless_linux.go

@@ -0,0 +1,165 @@
+// +build linux
+
+package wireless
+
+import (
+	"bytes"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+// default host proc path
+const defaultHostProc = "/proc"
+
+// env host proc variable name
+const envProc = "HOST_PROC"
+
+// length of wireless interface fields
+const interfaceFieldLength = 10
+
+var newLineByte = []byte("\n")
+
+type wirelessInterface struct {
+	Interface string
+	Status    int64
+	Link      int64
+	Level     int64
+	Noise     int64
+	Nwid      int64
+	Crypt     int64
+	Frag      int64
+	Retry     int64
+	Misc      int64
+	Beacon    int64
+}
+
+// Wireless is used to store configuration values.
+type Wireless struct {
+	HostProc string `toml:"host_proc"`
+}
+
+var sampleConfig = `
+  ## Sets 'proc' directory path
+  ## If not specified, then default is /proc
+  # host_proc = "/proc"
+`
+
+// Description returns information about the plugin.
+func (w *Wireless) Description() string {
+	return "Monitor wifi signal strength and quality"
+}
+
+// SampleConfig displays configuration instructions.
+func (w *Wireless) SampleConfig() string {
+	return sampleConfig
+}
+
+// Gather collects the wireless information.
+func (w *Wireless) Gather(acc telegraf.Accumulator) error {
+	// load proc path, get default value if config value and env variable are empty
+	w.loadPath()
+
+	wirelessPath := path.Join(w.HostProc, "net", "wireless")
+	table, err := ioutil.ReadFile(wirelessPath)
+	if err != nil {
+		return err
+	}
+
+	interfaces, err := loadWirelessTable(table)
+	if err != nil {
+		return err
+	}
+	for _, w := range interfaces {
+		tags := map[string]string{
+			"interface": w.Interface,
+		}
+		fieldsG := map[string]interface{}{
+			"status": w.Status,
+			"link":   w.Link,
+			"level":  w.Level,
+			"noise":  w.Noise,
+		}
+		fieldsC := map[string]interface{}{
+			"nwid":   w.Nwid,
+			"crypt":  w.Crypt,
+			"frag":   w.Frag,
+			"retry":  w.Retry,
+			"misc":   w.Misc,
+			"beacon": w.Beacon,
+		}
+		acc.AddGauge("wireless", fieldsG, tags)
+		acc.AddCounter("wireless", fieldsC, tags)
+	}
+
+	return nil
+}
+
+func loadWirelessTable(table []byte) ([]*wirelessInterface, error) {
+	var w []*wirelessInterface
+	lines := bytes.Split(table, newLineByte)
+
+	// iterate over interfaces
+	for i := 2; i < len(lines); i = i + 1 {
+		if len(lines[i]) == 0 {
+			continue
+		}
+		values := make([]int64, 0, interfaceFieldLength)
+		fields := strings.Fields(string(lines[i]))
+		for j := 1; j < len(fields); j = j + 1 {
+			v, err := strconv.ParseInt(strings.Trim(fields[j], "."), 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			values = append(values, v)
+		}
+		if len(values) != interfaceFieldLength {
+			log.Printf("E! [input.wireless] invalid length of interface values")
+			continue
+		}
+		w = append(w, &wirelessInterface{
+			Interface: strings.Trim(fields[0], ":"),
+			Status:    values[0],
+			Link:      values[1],
+			Level:     values[2],
+			Noise:     values[3],
+			Nwid:      values[4],
+			Crypt:     values[5],
+			Frag:      values[6],
+			Retry:     values[7],
+			Misc:      values[8],
+			Beacon:    values[9],
+		})
+	}
+	return w, nil
+}
+
+// loadPath can be used to read path firstly from config
+// if it is empty then try read from env variable
+func (w *Wireless) loadPath() {
+	if w.HostProc == "" {
+		w.HostProc = proc(envProc, defaultHostProc)
+	}
+}
+
+// proc can be used to read file paths from env
+func proc(env, path string) string {
+	// try to read full file path
+	if p := os.Getenv(env); p != "" {
+		return p
+	}
+	// return default path
+	return path
+}
+
+func init() {
+	inputs.Add("wireless", func() telegraf.Input {
+		return &Wireless{}
+	})
+}

plugins/inputs/wireless/wireless_test.go

@@ -0,0 +1,52 @@
+// +build linux
+
+package wireless
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var testInput = []byte(`Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
+ face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 22
+ wlan0: 0000   60.  -50.  -256        0      0      0   1525      0        0
+ wlan1: 0000   70.  -39.  -256        0      0      0  12096 191188        0`)
+
+func TestLoadWirelessTable(t *testing.T) {
+	expectedMetrics := []*wirelessInterface{
+		&wirelessInterface{
+			Interface: "wlan0",
+			Status:    int64(0000),
+			Link:      int64(60),
+			Level:     int64(-50),
+			Noise:     int64(-256),
+			Nwid:      int64(0),
+			Crypt:     int64(0),
+			Frag:      int64(0),
+			Retry:     int64(1525),
+			Misc:      int64(0),
+			Beacon:    int64(0),
+		},
+		&wirelessInterface{
+			Interface: "wlan1",
+			Status:    int64(0000),
+			Link:      int64(70),
+			Level:     int64(-39),
+			Noise:     int64(-256),
+			Nwid:      int64(0),
+			Crypt:     int64(0),
+			Frag:      int64(0),
+			Retry:     int64(12096),
+			Misc:      int64(191188),
+			Beacon:    int64(0),
+		},
+	}
+	metrics, err := loadWirelessTable(testInput)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	as := assert.New(t)
+	as.Equal(metrics, expectedMetrics)
+}