node_exporter/collector/netstat.go

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// +build !nonetStat
package collector
import (
"bufio"
"fmt"
"io"
"os"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
)
const (
procNetStat = "/proc/net/netstat"
netStatsSubsystem = "netstat"
)
var (
netStatsMetrics = map[string]prometheus.Gauge{}
)
type netStatCollector struct {
config Config
}
func init() {
Factories["netstat"] = NewNetStatCollector
}
// NewNetStatCollector takes a config struct and returns
// a new Collector exposing network stats.
func NewNetStatCollector(config Config) (Collector, error) {
c := netStatCollector{
config: config,
}
return &c, nil
}
func (c *netStatCollector) Update(ch chan<- prometheus.Metric) (err error) {
netStats, err := getNetStats()
if err != nil {
return fmt.Errorf("couldn't get netstats: %s", err)
}
for protocol, protocolStats := range netStats {
for name, value := range protocolStats {
key := protocol + "_" + name
if _, ok := netStatsMetrics[key]; !ok {
netStatsMetrics[key] = prometheus.NewGauge(
prometheus.GaugeOpts{
Namespace: Namespace,
Subsystem: netStatsSubsystem,
Name: key,
Help: fmt.Sprintf("%s %s from /proc/net/netstat.", protocol, name),
},
)
}
v, err := strconv.ParseFloat(value, 64)
if err != nil {
return fmt.Errorf("invalid value %s in netstats: %s", value, err)
}
netStatsMetrics[key].Set(v)
}
}
for _, m := range netStatsMetrics {
m.Collect(ch)
}
return err
}
func getNetStats() (map[string]map[string]string, error) {
file, err := os.Open(procNetStat)
if err != nil {
return nil, err
}
return parseNetStats(file)
}
func parseNetStats(r io.ReadCloser) (map[string]map[string]string, error) {
defer r.Close()
netStats := map[string]map[string]string{}
scanner := bufio.NewScanner(r)
for scanner.Scan() {
nameParts := strings.Split(string(scanner.Text()), " ")
scanner.Scan()
valueParts := strings.Split(string(scanner.Text()), " ")
// Remove trailing :.
protocol := nameParts[0][:len(nameParts[0])-1]
netStats[protocol] = map[string]string{}
if len(nameParts) != len(valueParts) {
return nil, fmt.Errorf("mismatch field count mismatch in %s: %s",
procNetStat, protocol)
}
for i := 1; i < len(nameParts); i++ {
netStats[protocol][nameParts[i]] = valueParts[i]
}
}
return netStats, nil
}