Node_Exporter/collector/sockstat_linux.go
2015-09-10 12:21:25 +02:00

116 lines
2.9 KiB
Go

// +build !nosockstat
package collector
import (
"bufio"
"fmt"
"github.com/prometheus/client_golang/prometheus"
"io"
"os"
"strconv"
"strings"
)
const (
procSockStat = "/proc/net/sockstat"
sockStatSubsystem = "sockstat"
)
// Used for calculating the total memory bytes on TCP and UDP.
var pageSize = os.Getpagesize()
type sockStatCollector struct {
metrics map[string]prometheus.Gauge
}
func init() {
Factories[sockStatSubsystem] = NewSockStatCollector
}
// NewSockStatCollector returns a new Collector exposing socket stats.
func NewSockStatCollector() (Collector, error) {
return &sockStatCollector{
metrics: map[string]prometheus.Gauge{},
}, nil
}
func (c *sockStatCollector) Update(ch chan<- prometheus.Metric) (err error) {
sockStats, err := getSockStats(procSockStat)
if err != nil {
return fmt.Errorf("couldn't get sockstats: %s", err)
}
for protocol, protocolStats := range sockStats {
for name, value := range protocolStats {
key := protocol + "_" + name
if _, ok := c.metrics[key]; !ok {
c.metrics[key] = prometheus.NewGauge(
prometheus.GaugeOpts{
Namespace: Namespace,
Subsystem: sockStatSubsystem,
Name: key,
Help: fmt.Sprintf("%s %s from /proc/net/sockstat.", protocol, name),
},
)
}
v, err := strconv.ParseFloat(value, 64)
if err != nil {
return fmt.Errorf("invalid value %s in sockstats: %s", value, err)
}
c.metrics[key].Set(v)
}
}
for _, m := range c.metrics {
m.Collect(ch)
}
return err
}
func getSockStats(fileName string) (map[string]map[string]string, error) {
file, err := os.Open(fileName)
if err != nil {
return nil, err
}
defer file.Close()
return parseSockStats(file, fileName)
}
func parseSockStats(r io.Reader, fileName string) (map[string]map[string]string, error) {
var (
sockStat = map[string]map[string]string{}
scanner = bufio.NewScanner(r)
)
for scanner.Scan() {
line := strings.Split(string(scanner.Text()), " ")
// Remove trailing ':'.
protocol := line[0][:len(line[0])-1]
sockStat[protocol] = map[string]string{}
for i := 1; i < len(line) && i+1 < len(line); i++ {
sockStat[protocol][line[i]] = line[i+1]
i++
}
}
// The mem metrics is the count of pages used. Multiply the mem metrics by
// the page size from the kernel to get the number of bytes used.
//
// Update the TCP mem from page count to bytes.
pageCount, err := strconv.Atoi(sockStat["TCP"]["mem"])
if err != nil {
return nil, fmt.Errorf("invalid value %s in sockstats: %s", sockStat["TCP"]["mem"], err)
}
sockStat["TCP"]["mem_bytes"] = strconv.Itoa(pageCount * pageSize)
// Update the UDP mem from page count to bytes.
pageCount, err = strconv.Atoi(sockStat["UDP"]["mem"])
if err != nil {
return nil, fmt.Errorf("invalid value %s in sockstats: %s", sockStat["UDP"]["mem"], err)
}
sockStat["UDP"]["mem_bytes"] = strconv.Itoa(pageCount * pageSize)
return sockStat, nil
}