node_exporter/collector/netdev.go
2015-05-28 21:22:03 +02:00

131 lines
3 KiB
Go

// +build !nonetdev
package collector
import (
"bufio"
"fmt"
"io"
"os"
"regexp"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
)
const (
procNetDev = "/proc/net/dev"
netDevSubsystem = "network"
)
var (
fieldSep = regexp.MustCompile("[ :] *")
)
type netDevCollector struct {
metrics map[string]*prometheus.GaugeVec
}
func init() {
Factories["netdev"] = NewNetDevCollector
}
// Takes a prometheus registry and returns a new Collector exposing
// network device stats.
func NewNetDevCollector() (Collector, error) {
return &netDevCollector{
metrics: map[string]*prometheus.GaugeVec{},
}, nil
}
func (c *netDevCollector) Update(ch chan<- prometheus.Metric) (err error) {
netDev, err := getNetDevStats()
if err != nil {
return fmt.Errorf("Couldn't get netstats: %s", err)
}
for direction, devStats := range netDev {
for dev, stats := range devStats {
for t, value := range stats {
key := direction + "_" + t
if _, ok := c.metrics[key]; !ok {
c.metrics[key] = prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: Namespace,
Subsystem: netDevSubsystem,
Name: key,
Help: fmt.Sprintf("%s %s from /proc/net/dev.", t, direction),
},
[]string{"device"},
)
}
v, err := strconv.ParseFloat(value, 64)
if err != nil {
return fmt.Errorf("Invalid value %s in netstats: %s", value, err)
}
c.metrics[key].WithLabelValues(dev).Set(v)
}
}
}
for _, m := range c.metrics {
m.Collect(ch)
}
return err
}
func getNetDevStats() (map[string]map[string]map[string]string, error) {
file, err := os.Open(procNetDev)
if err != nil {
return nil, err
}
defer file.Close()
return parseNetDevStats(file)
}
func parseNetDevStats(r io.Reader) (map[string]map[string]map[string]string, error) {
netDev := map[string]map[string]map[string]string{}
netDev["transmit"] = map[string]map[string]string{}
netDev["receive"] = map[string]map[string]string{}
scanner := bufio.NewScanner(r)
scanner.Scan() // skip first header
scanner.Scan()
parts := strings.Split(string(scanner.Text()), "|")
if len(parts) != 3 { // interface + receive + transmit
return nil, fmt.Errorf("Invalid header line in %s: %s",
procNetDev, scanner.Text())
}
header := strings.Fields(parts[1])
for scanner.Scan() {
line := strings.TrimLeft(string(scanner.Text()), " ")
parts := fieldSep.Split(line, -1)
if len(parts) != 2*len(header)+1 {
return nil, fmt.Errorf("Invalid line in %s: %s",
procNetDev, scanner.Text())
}
dev := parts[0][:len(parts[0])]
receive, err := parseNetDevLine(parts[1:len(header)+1], header)
if err != nil {
return nil, err
}
transmit, err := parseNetDevLine(parts[len(header)+1:], header)
if err != nil {
return nil, err
}
netDev["transmit"][dev] = transmit
netDev["receive"][dev] = receive
}
return netDev, nil
}
func parseNetDevLine(parts []string, header []string) (map[string]string, error) {
devStats := map[string]string{}
for i, v := range parts {
devStats[header[i]] = v
}
return devStats, nil
}