Node_Exporter/collector/filefd_linux.go
2017-02-28 13:57:49 -04:00

88 lines
2.4 KiB
Go

// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build !nofilefd
package collector
import (
"bufio"
"fmt"
"io"
"os"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
)
const (
fileFDStatSubsystem = "filefd"
)
type fileFDStatCollector struct{}
func init() {
Factories[fileFDStatSubsystem] = NewFileFDStatCollector
}
// NewFileFDStatCollector returns a new Collector exposing file-nr stats.
func NewFileFDStatCollector() (Collector, error) {
return &fileFDStatCollector{}, nil
}
func (c *fileFDStatCollector) Update(ch chan<- prometheus.Metric) (err error) {
fileFDStat, err := getFileFDStats(procFilePath("sys/fs/file-nr"))
if err != nil {
return fmt.Errorf("couldn't get file-nr: %s", err)
}
for name, value := range fileFDStat {
v, err := strconv.ParseFloat(value, 64)
if err != nil {
return fmt.Errorf("invalid value %s in file-nr: %s", value, err)
}
ch <- prometheus.MustNewConstMetric(
prometheus.NewDesc(
prometheus.BuildFQName(Namespace, fileFDStatSubsystem, name),
fmt.Sprintf("File descriptor statistics: %s.", name),
nil, nil,
),
prometheus.GaugeValue, v,
)
}
return nil
}
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(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 always be zero in linux 2.6.
fileFDStat["maximum"] = line[2]
return fileFDStat, nil
}