node_exporter/collector/filefd_linux.go
Ken Herner 7569c6ce23 Initial implementation of file-nr
Fixed file-nr update function

Fixed file-nr test case

Fixed file-nr test case again

Fixed file-nr separator to tab

Updated file-nr to filenr.

Updated file-nr to filenr.

Fixed file-nr test cases, added comments

Remove reporting the second value from file-nr as it will alwasy be zero in linux 2.6 and greator

Renaming file-nr to filefd

Updated build constraint

Updates and code cleanup for filefd.

Updated enabledCollectors with the correct name for filefd

Fixed filefd test wording
2015-09-10 10:27:58 -04:00

85 lines
2 KiB
Go

// +build !nofilefd
package collector
import (
"bufio"
"fmt"
"github.com/prometheus/client_golang/prometheus"
"io"
"os"
"strconv"
"strings"
)
const (
procFileFDStat = "/proc/sys/fs/file-nr"
fileFDStatSubsystem = "filefd"
)
type fileFDStatCollector struct {
metrics map[string]prometheus.Gauge
}
func init() {
Factories[fileFDStatSubsystem] = NewFileFDStatCollector
}
// NewFileFDStatCollector returns a new Collector exposing file-nr stats.
func NewFileFDStatCollector() (Collector, error) {
return &fileFDStatCollector{
metrics: map[string]prometheus.Gauge{},
}, nil
}
func (c *fileFDStatCollector) Update(ch chan<- prometheus.Metric) (err error) {
fileFDStat, err := getFileFDStats(procFileFDStat)
if err != nil {
return fmt.Errorf("couldn't get file-nr: %s", err)
}
for name, value := range fileFDStat {
if _, ok := c.metrics[name]; !ok {
c.metrics[name] = prometheus.NewGauge(
prometheus.GaugeOpts{
Namespace: Namespace,
Subsystem: fileFDStatSubsystem,
Name: name,
Help: fmt.Sprintf("filefd %s from %s.", name, procFileFDStat),
},
)
v, err := strconv.ParseFloat(value, 64)
if err != nil {
return fmt.Errorf("invalid value %s in file-nr: %s", value, err)
}
c.metrics[name].Set(v)
}
}
for _, m := range c.metrics {
m.Collect(ch)
}
return err
}
func getFileFDStats(fileName string) (map[string]string, error) {
file, err := os.Open(fileName)
if err != nil {
return nil, err
}
defer file.Close()
return parseFileFDStats(file, fileName)
}
func parseFileFDStats(r io.Reader, fileName string) (map[string]string, error) {
var scanner = bufio.NewScanner(r)
scanner.Scan()
// The file-nr proc file is separated by tabs, not spaces.
line := strings.Split(string(scanner.Text()), "\u0009")
var fileFDStat = map[string]string{}
// The file-nr proc is only 1 line with 3 values.
fileFDStat["allocated"] = line[0]
// The second value is skipped as it will alwasy be zero in linux 2.6.
fileFDStat["maximum"] = line[2]
return fileFDStat, nil
}