nstat input plugin

plugins/inputs/nstat/nstat.go

@@ -0,0 +1,183 @@
+package nstat
+
+import (
+	"bytes"
+	"io/ioutil"
+	"strconv"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+var (
+	zeroByte    = []byte("0")
+	newLineByte = []byte("\n")
+	colonByte   = []byte(":")
+)
+
+type Nstat struct {
+	ProcNetNetstat string `toml:"proc_net_netstat"`
+	ProcNetSNMP    string `toml:"proc_net_snmp"`
+	ProcNetSNMP6   string `toml:"proc_net_snmp6"`
+	DumpZeros      bool   `toml:"dump_zeros"`
+}
+
+var sampleConfig = `
+	# file paths
+	proc_net_netstat 	= 	"/proc/net/netstat"
+	proc_net_snmp 		= 	"/proc/net/snmp"
+	proc_net_snmp6 		= 	"/proc/net/snmp6"
+	# dump metrics with 0 values too
+	dump_zeros			= 	true
+`
+
+func (ns *Nstat) Description() string {
+	return "Collect network metrics from '/proc/net/netstat', '/proc/net/snmp' & '/proc/net/snmp6' files"
+}
+
+func (ns *Nstat) SampleConfig() string {
+	return sampleConfig
+}
+
+func (ns *Nstat) Gather(acc telegraf.Accumulator) error {
+	netstat, err := ioutil.ReadFile(ns.ProcNetNetstat)
+	if err != nil {
+		return err
+	}
+
+	// collect netstat data
+	err = ns.gatherNetstat(netstat, acc)
+	if err != nil {
+		return err
+	}
+
+	// collect SNMP data
+	snmp, err := ioutil.ReadFile(ns.ProcNetSNMP)
+	if err != nil {
+		return err
+	}
+	err = ns.gatherSNMP(snmp, acc)
+	if err != nil {
+		return err
+	}
+
+	// collect SNMP6 data
+	snmp6, err := ioutil.ReadFile(ns.ProcNetSNMP6)
+	if err != nil {
+		return err
+	}
+	err = ns.gatherSNMP6(snmp6, acc)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ns *Nstat) gatherNetstat(data []byte, acc telegraf.Accumulator) error {
+	metrics, err := loadUglyTable(data, ns.DumpZeros)
+	if err != nil {
+		return err
+	}
+	tags := map[string]string{
+		"name": "netstat",
+	}
+	acc.AddFields("nstat", metrics, tags)
+	return nil
+}
+
+func (ns *Nstat) gatherSNMP(data []byte, acc telegraf.Accumulator) error {
+	metrics, err := loadUglyTable(data, ns.DumpZeros)
+	if err != nil {
+		return err
+	}
+	tags := map[string]string{
+		"name": "snmp",
+	}
+	acc.AddFields("nstat", metrics, tags)
+	return nil
+}
+
+func (ns *Nstat) gatherSNMP6(data []byte, acc telegraf.Accumulator) error {
+	metrics, err := loadGoodTable(data, ns.DumpZeros)
+	if err != nil {
+		return err
+	}
+	tags := map[string]string{
+		"name": "snmp6",
+	}
+	acc.AddFields("nstat", metrics, tags)
+	return nil
+}
+
+// loadGoodTable can be used to parse string heap that
+// headers and values are arranged in right order
+func loadGoodTable(table []byte, dumpZeros bool) (map[string]interface{}, error) {
+	entries := map[string]interface{}{}
+	fields := bytes.Fields(table)
+	var value int64
+	var err error
+	// iterate over two values each time
+	// first value is header, second is value
+	for i := 0; i < len(fields); i = i + 2 {
+		// counter is zero
+		if bytes.Equal(fields[i+1], zeroByte) {
+			if !dumpZeros {
+				continue
+			} else {
+				entries[string(fields[i])] = int64(0)
+				continue
+			}
+		}
+		// the counter is not zero, so parse it.
+		value, err = strconv.ParseInt(string(fields[i+1]), 10, 64)
+		if err == nil {
+			entries[string(fields[i])] = value
+		}
+	}
+	return entries, nil
+}
+
+// loadUglyTable can be used to parse string heap that
+// the headers and values are splitted with a newline
+func loadUglyTable(table []byte, dumpZeros bool) (map[string]interface{}, error) {
+	entries := map[string]interface{}{}
+	// split the lines by newline
+	lines := bytes.Split(table, newLineByte)
+	var value int64
+	var err error
+	// iterate over lines, take 2 lines each time
+	// first line contains header names
+	// second line contains values
+	for i := 0; i < len(lines); i = i + 2 {
+		if len(lines[i]) == 0 {
+			continue
+		}
+		headers := bytes.Fields(lines[i])
+		prefix := bytes.TrimSuffix(headers[0], colonByte)
+		metrics := bytes.Fields(lines[i+1])
+
+		for j := 1; j < len(headers); j++ {
+			// counter is zero
+			if bytes.Equal(metrics[j], zeroByte) {
+				if !dumpZeros {
+					continue
+				} else {
+					entries[string(append(prefix, headers[j]...))] = int64(0)
+					continue
+				}
+			}
+			// the counter is not zero, so parse it.
+			value, err = strconv.ParseInt(string(metrics[j]), 10, 64)
+			if err == nil {
+				entries[string(append(prefix, headers[j]...))] = value
+			}
+		}
+	}
+	return entries, nil
+}
+
+func init() {
+	inputs.Add("nstat", func() telegraf.Input {
+		return &Nstat{}
+	})
+}